gecko/dom/media/MediaManager.cpp

/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "MediaManager.h"

#include "MediaStreamGraph.h"
#include "mozilla/dom/MediaStreamTrack.h"
#include "GetUserMediaRequest.h"
#include "nsHashPropertyBag.h"
#ifdef MOZ_WIDGET_GONK
#include "nsIAudioManager.h"
#endif
#include "nsIEventTarget.h"
#include "nsIUUIDGenerator.h"
#include "nsIScriptGlobalObject.h"
#include "nsIPermissionManager.h"
#include "nsIPopupWindowManager.h"
#include "nsISupportsArray.h"
#include "nsIDocShell.h"
#include "nsIDocument.h"
#include "nsISupportsPrimitives.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIIDNService.h"
#include "nsNetCID.h"
#include "nsNetUtil.h"
#include "nsPrincipal.h"
#include "nsICryptoHash.h"
#include "nsICryptoHMAC.h"
#include "nsIKeyModule.h"
#include "nsAppDirectoryServiceDefs.h"
#include "nsIInputStream.h"
#include "nsILineInputStream.h"
#include "mozilla/Types.h"
#include "mozilla/PeerIdentity.h"
#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/MediaStreamBinding.h"
#include "mozilla/dom/MediaStreamTrackBinding.h"
#include "mozilla/dom/GetUserMediaRequestBinding.h"
#include "mozilla/Preferences.h"
#include "mozilla/Base64.h"
#include "mozilla/ipc/BackgroundChild.h"
#include "mozilla/media/MediaChild.h"
#include "MediaTrackConstraints.h"
#include "VideoUtils.h"
#include "Latency.h"
#include "nsProxyRelease.h"
#include "nsNullPrincipal.h"

// For PR_snprintf
#include "prprf.h"

#include "nsJSUtils.h"
#include "nsGlobalWindow.h"
#include "nsIUUIDGenerator.h"
#include "nspr.h"
#include "nss.h"
#include "pk11pub.h"

/* Using WebRTC backend on Desktops (Mac, Windows, Linux), otherwise default */
#include "MediaEngineDefault.h"
#if defined(MOZ_WEBRTC)
#include "MediaEngineWebRTC.h"
#include "browser_logging/WebRtcLog.h"
#endif

#ifdef MOZ_B2G
#include "MediaPermissionGonk.h"
#endif

#if defined(XP_MACOSX)
#include "nsCocoaFeatures.h"
#endif
#if defined (XP_WIN)
#include "mozilla/WindowsVersion.h"
#endif

#include <map>

// GetCurrentTime is defined in winbase.h as zero argument macro forwarding to
// GetTickCount() and conflicts with MediaStream::GetCurrentTime.
#ifdef GetCurrentTime
#undef GetCurrentTime
#endif

// XXX Workaround for bug 986974 to maintain the existing broken semantics
template<>
struct nsIMediaDevice::COMTypeInfo<mozilla::VideoDevice, void> {
  static const nsIID kIID;
};
const nsIID nsIMediaDevice::COMTypeInfo<mozilla::VideoDevice, void>::kIID = NS_IMEDIADEVICE_IID;
template<>
struct nsIMediaDevice::COMTypeInfo<mozilla::AudioDevice, void> {
  static const nsIID kIID;
};
const nsIID nsIMediaDevice::COMTypeInfo<mozilla::AudioDevice, void>::kIID = NS_IMEDIADEVICE_IID;

namespace mozilla {

#ifdef LOG
#undef LOG
#endif

PRLogModuleInfo*
GetMediaManagerLog()
{
  static PRLogModuleInfo *sLog;
  if (!sLog)
    sLog = PR_NewLogModule("MediaManager");
  return sLog;
}
#define LOG(msg) MOZ_LOG(GetMediaManagerLog(), mozilla::LogLevel::Debug, msg)

using dom::File;
using dom::MediaStreamConstraints;
using dom::MediaTrackConstraintSet;
using dom::MediaTrackConstraints;
using dom::MediaStreamError;
using dom::GetUserMediaRequest;
using dom::Sequence;
using dom::OwningBooleanOrMediaTrackConstraints;
using media::Pledge;
using media::NewRunnableFrom;
using media::NewTaskFrom;

static Atomic<bool> sInShutdown;

static bool
HostInDomain(const nsCString &aHost, const nsCString &aPattern)
{
  int32_t patternOffset = 0;
  int32_t hostOffset = 0;

  // Act on '*.' wildcard in the left-most position in a domain pattern.
  if (aPattern.Length() > 2 && aPattern[0] == '*' && aPattern[1] == '.') {
    patternOffset = 2;

    // Ignore the lowest level sub-domain for the hostname.
    hostOffset = aHost.FindChar('.') + 1;

    if (hostOffset <= 1) {
      // Reject a match between a wildcard and a TLD or '.foo' form.
      return false;
    }
  }

  nsDependentCString hostRoot(aHost, hostOffset);
  return hostRoot.EqualsIgnoreCase(aPattern.BeginReading() + patternOffset);
}

static bool
HostHasPermission(nsIURI &docURI)
{
  nsresult rv;

  bool isHttps;
  rv = docURI.SchemeIs("https",&isHttps);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return false;
  }
  if (!isHttps) {
    return false;
  }

  nsAdoptingCString hostName;
  docURI.GetAsciiHost(hostName); //normalize UTF8 to ASCII equivalent
  nsAdoptingCString domainWhiteList =
    Preferences::GetCString("media.getusermedia.screensharing.allowed_domains");
  domainWhiteList.StripWhitespace();

  if (domainWhiteList.IsEmpty() || hostName.IsEmpty()) {
    return false;
  }

  // Get UTF8 to ASCII domain name normalization service
  nsCOMPtr<nsIIDNService> idnService
    = do_GetService("@mozilla.org/network/idn-service;1", &rv);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return false;
  }

  uint32_t begin = 0;
  uint32_t end = 0;
  nsCString domainName;
  /*
     Test each domain name in the comma separated list
     after converting from UTF8 to ASCII. Each domain
     must match exactly or have a single leading '*.' wildcard
  */
  do {
    end = domainWhiteList.FindChar(',', begin);
    if (end == (uint32_t)-1) {
      // Last or only domain name in the comma separated list
      end = domainWhiteList.Length();
    }

    rv = idnService->ConvertUTF8toACE(Substring(domainWhiteList, begin, end - begin),
                                      domainName);
    if (NS_SUCCEEDED(rv)) {
      if (HostInDomain(hostName, domainName)) {
        return true;
      }
    } else {
      NS_WARNING("Failed to convert UTF-8 host to ASCII");
    }

    begin = end + 1;
  } while (end < domainWhiteList.Length());

  return false;
}

/**
 * Send an error back to content.
 * Do this only on the main thread. The onSuccess callback is also passed here
 * so it can be released correctly.
 */
template<class SuccessCallbackType>
class ErrorCallbackRunnable : public nsRunnable
{
public:
  ErrorCallbackRunnable(
    nsCOMPtr<SuccessCallbackType>& aOnSuccess,
    nsCOMPtr<nsIDOMGetUserMediaErrorCallback>& aOnFailure,
    MediaMgrError& aError,
    uint64_t aWindowID)
    : mError(&aError)
    , mWindowID(aWindowID)
    , mManager(MediaManager::GetInstance())
  {
    mOnSuccess.swap(aOnSuccess);
    mOnFailure.swap(aOnFailure);
  }

  NS_IMETHODIMP
  Run()
  {
    NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");

    nsCOMPtr<SuccessCallbackType> onSuccess = mOnSuccess.forget();
    nsCOMPtr<nsIDOMGetUserMediaErrorCallback> onFailure = mOnFailure.forget();

    // Only run if the window is still active.
    if (!(mManager->IsWindowStillActive(mWindowID))) {
      return NS_OK;
    }
    // This is safe since we're on main-thread, and the windowlist can only
    // be invalidated from the main-thread (see OnNavigation)
    nsGlobalWindow* window = nsGlobalWindow::GetInnerWindowWithId(mWindowID);
    if (window) {
      nsRefPtr<MediaStreamError> error = new MediaStreamError(window, *mError);
      onFailure->OnError(error);
    }
    return NS_OK;
  }
private:
  ~ErrorCallbackRunnable()
  {
    MOZ_ASSERT(!mOnSuccess && !mOnFailure);
  }

  nsCOMPtr<SuccessCallbackType> mOnSuccess;
  nsCOMPtr<nsIDOMGetUserMediaErrorCallback> mOnFailure;
  nsRefPtr<MediaMgrError> mError;
  uint64_t mWindowID;
  nsRefPtr<MediaManager> mManager; // get ref to this when creating the runnable
};

// Handle removing GetUserMediaCallbackMediaStreamListener from main thread
class GetUserMediaListenerRemove: public nsRunnable
{
public:
  GetUserMediaListenerRemove(uint64_t aWindowID,
    GetUserMediaCallbackMediaStreamListener *aListener)
    : mWindowID(aWindowID)
    , mListener(aListener) {}

  NS_IMETHOD
  Run()
  {
    NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
    nsRefPtr<MediaManager> manager(MediaManager::GetInstance());
    manager->RemoveFromWindowList(mWindowID, mListener);
    return NS_OK;
  }

protected:
  uint64_t mWindowID;
  nsRefPtr<GetUserMediaCallbackMediaStreamListener> mListener;
};

/**
 * nsIMediaDevice implementation.
 */
NS_IMPL_ISUPPORTS(MediaDevice, nsIMediaDevice)

MediaDevice::MediaDevice(MediaEngineSource* aSource, bool aIsVideo)
  : mMediaSource(aSource->GetMediaSource())
  , mSource(aSource)
  , mIsVideo(aIsVideo)
{
  mSource->GetName(mName);
  nsCString id;
  mSource->GetUUID(id);
  CopyUTF8toUTF16(id, mID);
}

VideoDevice::VideoDevice(MediaEngineVideoSource* aSource)
  : MediaDevice(aSource, true)
{}

/**
 * Helper functions that implement the constraints algorithm from
 * http://dev.w3.org/2011/webrtc/editor/getusermedia.html#methods-5
 */

bool
MediaDevice::StringsContain(const OwningStringOrStringSequence& aStrings,
                            nsString aN)
{
  return aStrings.IsString() ? aStrings.GetAsString() == aN
                             : aStrings.GetAsStringSequence().Contains(aN);
}

/* static */ uint32_t
MediaDevice::FitnessDistance(nsString aN,
                             const ConstrainDOMStringParameters& aParams)
{
  if (aParams.mExact.WasPassed() && !StringsContain(aParams.mExact.Value(), aN)) {
    return UINT32_MAX;
  }
  if (aParams.mIdeal.WasPassed() && !StringsContain(aParams.mIdeal.Value(), aN)) {
    return 1;
  }
  return 0;
}

// Binding code doesn't templatize well...

/* static */ uint32_t
MediaDevice::FitnessDistance(nsString aN,
    const OwningStringOrStringSequenceOrConstrainDOMStringParameters& aConstraint)
{
  if (aConstraint.IsString()) {
    ConstrainDOMStringParameters params;
    params.mIdeal.Construct();
    params.mIdeal.Value().SetAsString() = aConstraint.GetAsString();
    return FitnessDistance(aN, params);
  } else if (aConstraint.IsStringSequence()) {
    ConstrainDOMStringParameters params;
    params.mIdeal.Construct();
    params.mIdeal.Value().SetAsStringSequence() = aConstraint.GetAsStringSequence();
    return FitnessDistance(aN, params);
  } else {
    return FitnessDistance(aN, aConstraint.GetAsConstrainDOMStringParameters());
  }
}

// Reminder: add handling for new constraints both here and in GetSources below!

uint32_t
MediaDevice::GetBestFitnessDistance(
    const nsTArray<const MediaTrackConstraintSet*>& aConstraintSets)
{
  nsString mediaSource;
  GetMediaSource(mediaSource);

  // This code is reused for audio, where the mediaSource constraint does
  // not currently have a function, but because it defaults to "camera" in
  // webidl, we ignore it for audio here.
  if (!mediaSource.EqualsASCII("microphone")) {
    for (const auto& constraint : aConstraintSets) {
      if (mediaSource != constraint->mMediaSource) {
        return UINT32_MAX;
      }
    }
  }
  // Forward request to underlying object to interrogate per-mode capabilities.
  // Pass in device's origin-specific id for deviceId constraint comparison.
  nsString id;
  GetId(id);
  return mSource->GetBestFitnessDistance(aConstraintSets, id);
}

AudioDevice::AudioDevice(MediaEngineAudioSource* aSource)
  : MediaDevice(aSource, false)
{
  mMediaSource = aSource->GetMediaSource();
}

NS_IMETHODIMP
MediaDevice::GetName(nsAString& aName)
{
  aName.Assign(mName);
  return NS_OK;
}

NS_IMETHODIMP
MediaDevice::GetType(nsAString& aType)
{
  return NS_OK;
}

NS_IMETHODIMP
VideoDevice::GetType(nsAString& aType)
{
  aType.AssignLiteral(MOZ_UTF16("video"));
  return NS_OK;
}

NS_IMETHODIMP
AudioDevice::GetType(nsAString& aType)
{
  aType.AssignLiteral(MOZ_UTF16("audio"));
  return NS_OK;
}

NS_IMETHODIMP
MediaDevice::GetId(nsAString& aID)
{
  aID.Assign(mID);
  return NS_OK;
}

void
MediaDevice::SetId(const nsAString& aID)
{
  mID.Assign(aID);
}

NS_IMETHODIMP
MediaDevice::GetMediaSource(nsAString& aMediaSource)
{
  if (mMediaSource == dom::MediaSourceEnum::Microphone) {
    aMediaSource.Assign(NS_LITERAL_STRING("microphone"));
  } else if (mMediaSource == dom::MediaSourceEnum::AudioCapture) {
    aMediaSource.Assign(NS_LITERAL_STRING("audioCapture"));
  } else if (mMediaSource == dom::MediaSourceEnum::Window) { // this will go away
    aMediaSource.Assign(NS_LITERAL_STRING("window"));
  } else { // all the rest are shared
    aMediaSource.Assign(NS_ConvertUTF8toUTF16(
      dom::MediaSourceEnumValues::strings[uint32_t(mMediaSource)].value));
  }
  return NS_OK;
}

VideoDevice::Source*
VideoDevice::GetSource()
{
  return static_cast<Source*>(&*mSource);
}

AudioDevice::Source*
AudioDevice::GetSource()
{
  return static_cast<Source*>(&*mSource);
}

nsresult VideoDevice::Allocate(const dom::MediaTrackConstraints &aConstraints,
                               const MediaEnginePrefs &aPrefs) {
  return GetSource()->Allocate(aConstraints, aPrefs, mID);
}

nsresult AudioDevice::Allocate(const dom::MediaTrackConstraints &aConstraints,
                               const MediaEnginePrefs &aPrefs) {
  return GetSource()->Allocate(aConstraints, aPrefs, mID);
}

/**
 * A subclass that we only use to stash internal pointers to MediaStreamGraph objects
 * that need to be cleaned up.
 */
class nsDOMUserMediaStream : public DOMLocalMediaStream
{
public:
  static already_AddRefed<nsDOMUserMediaStream>
  CreateTrackUnionStream(nsIDOMWindow* aWindow,
                         GetUserMediaCallbackMediaStreamListener* aListener,
                         MediaEngineSource* aAudioSource,
                         MediaEngineSource* aVideoSource,
                         MediaStreamGraph* aMSG)
  {
    nsRefPtr<nsDOMUserMediaStream> stream = new nsDOMUserMediaStream(aListener,
                                                                     aAudioSource,
                                                                     aVideoSource);
    stream->InitTrackUnionStream(aWindow, aMSG);
    return stream.forget();
  }

  nsDOMUserMediaStream(GetUserMediaCallbackMediaStreamListener* aListener,
                       MediaEngineSource *aAudioSource,
                       MediaEngineSource *aVideoSource) :
    mListener(aListener),
    mAudioSource(aAudioSource),
    mVideoSource(aVideoSource),
    mEchoOn(true),
    mAgcOn(false),
    mNoiseOn(true),
#ifdef MOZ_WEBRTC
    mEcho(webrtc::kEcDefault),
    mAgc(webrtc::kAgcDefault),
    mNoise(webrtc::kNsDefault),
#else
    mEcho(0),
    mAgc(0),
    mNoise(0),
#endif
    mPlayoutDelay(20)
  {}

  virtual ~nsDOMUserMediaStream()
  {
    Stop();

    if (mPort) {
      mPort->Destroy();
    }
    if (mSourceStream) {
      mSourceStream->Destroy();
    }
  }

  virtual void Stop() override
  {
    if (mSourceStream) {
      mSourceStream->EndAllTrackAndFinish();
    }
  }

  // For gUM streams, we have a trackunion which assigns TrackIDs.  However, for a
  // single-source trackunion like we have here, the TrackUnion will assign trackids
  // that match the source's trackids, so we can avoid needing a mapping function.
  // XXX This will not handle more complex cases well.
  virtual void StopTrack(TrackID aTrackID) override
  {
    if (mSourceStream) {
      mSourceStream->EndTrack(aTrackID);
      // We could override NotifyMediaStreamTrackEnded(), and maybe should, but it's
      // risky to do late in a release since that will affect all track ends, and not
      // just StopTrack()s.
      if (GetDOMTrackFor(aTrackID)) {
        mListener->StopTrack(aTrackID, !!GetDOMTrackFor(aTrackID)->AsAudioStreamTrack());
      } else {
        LOG(("StopTrack(%d) on non-existant track", aTrackID));
      }
    }
  }

#if 0
  virtual void NotifyMediaStreamTrackEnded(dom::MediaStreamTrack* aTrack)
  {
    TrackID trackID = aTrack->GetTrackID();
    // We override this so we can also tell the backend to stop capturing if the track ends
    LOG(("track %d ending, type = %s",
         trackID, aTrack->AsAudioStreamTrack() ? "audio" : "video"));
    MOZ_ASSERT(aTrack->AsVideoStreamTrack() || aTrack->AsAudioStreamTrack());
    mListener->StopTrack(trackID, !!aTrack->AsAudioStreamTrack());

    // forward to superclass
    DOMLocalMediaStream::NotifyMediaStreamTrackEnded(aTrack);
  }
#endif

  // Allow getUserMedia to pass input data directly to PeerConnection/MediaPipeline
  virtual bool AddDirectListener(MediaStreamDirectListener *aListener) override
  {
    if (mSourceStream) {
      mSourceStream->AddDirectListener(aListener);
      return true; // application should ignore NotifyQueuedTrackData
    }
    return false;
  }

  virtual void
  AudioConfig(bool aEchoOn, uint32_t aEcho,
              bool aAgcOn, uint32_t aAgc,
              bool aNoiseOn, uint32_t aNoise,
              int32_t aPlayoutDelay)
  {
    mEchoOn = aEchoOn;
    mEcho = aEcho;
    mAgcOn = aAgcOn;
    mAgc = aAgc;
    mNoiseOn = aNoiseOn;
    mNoise = aNoise;
    mPlayoutDelay = aPlayoutDelay;
  }

  virtual void RemoveDirectListener(MediaStreamDirectListener *aListener) override
  {
    if (mSourceStream) {
      mSourceStream->RemoveDirectListener(aListener);
    }
  }

  // let us intervene for direct listeners when someone does track.enabled = false
  virtual void SetTrackEnabled(TrackID aID, bool aEnabled) override
  {
    // We encapsulate the SourceMediaStream and TrackUnion into one entity, so
    // we can handle the disabling at the SourceMediaStream

    // We need to find the input track ID for output ID aID, so we let the TrackUnion
    // forward the request to the source and translate the ID
    GetStream()->AsProcessedStream()->ForwardTrackEnabled(aID, aEnabled);
  }

  virtual DOMLocalMediaStream* AsDOMLocalMediaStream() override
  {
    return this;
  }

  virtual MediaEngineSource* GetMediaEngine(TrackID aTrackID) override
  {
    // MediaEngine supports only one video and on video track now and TrackID is
    // fixed in MediaEngine.
    if (aTrackID == kVideoTrack) {
      return mVideoSource;
    }
    else if (aTrackID == kAudioTrack) {
      return mAudioSource;
    }

    return nullptr;
  }

  // The actual MediaStream is a TrackUnionStream. But these resources need to be
  // explicitly destroyed too.
  nsRefPtr<SourceMediaStream> mSourceStream;
  nsRefPtr<MediaInputPort> mPort;
  nsRefPtr<GetUserMediaCallbackMediaStreamListener> mListener;
  nsRefPtr<MediaEngineSource> mAudioSource; // so we can turn on AEC
  nsRefPtr<MediaEngineSource> mVideoSource;
  bool mEchoOn;
  bool mAgcOn;
  bool mNoiseOn;
  uint32_t mEcho;
  uint32_t mAgc;
  uint32_t mNoise;
  uint32_t mPlayoutDelay;
};


void
MediaOperationTask::ReturnCallbackError(nsresult rv, const char* errorLog)
{
  MM_LOG(("%s , rv=%d", errorLog, rv));
  NS_DispatchToMainThread(do_AddRef(new ReleaseMediaOperationResource(mStream.forget(),
    mOnTracksAvailableCallback.forget())));
  nsString log;

  log.AssignASCII(errorLog);
  nsCOMPtr<nsIDOMGetUserMediaSuccessCallback> onSuccess;
  nsRefPtr<MediaMgrError> error = new MediaMgrError(
    NS_LITERAL_STRING("InternalError"), log);
  NS_DispatchToMainThread(do_AddRef(
    new ErrorCallbackRunnable<nsIDOMGetUserMediaSuccessCallback>(onSuccess,
                                                                 mOnFailure,
                                                                 *error,
                                                                 mWindowID)));
}

/**
 * Creates a MediaStream, attaches a listener and fires off a success callback
 * to the DOM with the stream. We also pass in the error callback so it can
 * be released correctly.
 *
 * All of this must be done on the main thread!
 *
 * Note that the various GetUserMedia Runnable classes currently allow for
 * two streams.  If we ever need to support getting more than two streams
 * at once, we could convert everything to nsTArray<nsRefPtr<blah> >'s,
 * though that would complicate the constructors some.  Currently the
 * GetUserMedia spec does not allow for more than 2 streams to be obtained in
 * one call, to simplify handling of constraints.
 */
class GetUserMediaStreamRunnable : public nsRunnable
{
public:
  GetUserMediaStreamRunnable(
    nsCOMPtr<nsIDOMGetUserMediaSuccessCallback>& aOnSuccess,
    nsCOMPtr<nsIDOMGetUserMediaErrorCallback>& aOnFailure,
    uint64_t aWindowID,
    GetUserMediaCallbackMediaStreamListener* aListener,
    const nsCString& aOrigin,
    MediaEngineSource* aAudioSource,
    MediaEngineSource* aVideoSource,
    PeerIdentity* aPeerIdentity)
    : mAudioSource(aAudioSource)
    , mVideoSource(aVideoSource)
    , mWindowID(aWindowID)
    , mListener(aListener)
    , mOrigin(aOrigin)
    , mPeerIdentity(aPeerIdentity)
    , mManager(MediaManager::GetInstance())
  {
    mOnSuccess.swap(aOnSuccess);
    mOnFailure.swap(aOnFailure);
  }

  ~GetUserMediaStreamRunnable() {}

  class TracksAvailableCallback : public DOMMediaStream::OnTracksAvailableCallback
  {
  public:
    TracksAvailableCallback(MediaManager* aManager,
                            nsIDOMGetUserMediaSuccessCallback* aSuccess,
                            uint64_t aWindowID,
                            DOMMediaStream* aStream)
      : mWindowID(aWindowID), mOnSuccess(aSuccess), mManager(aManager),
        mStream(aStream) {}
    virtual void NotifyTracksAvailable(DOMMediaStream* aStream) override
    {
      // We're in the main thread, so no worries here.
      if (!(mManager->IsWindowStillActive(mWindowID))) {
        return;
      }

      // Start currentTime from the point where this stream was successfully
      // returned.
      aStream->SetLogicalStreamStartTime(aStream->GetStream()->GetCurrentTime());

      // This is safe since we're on main-thread, and the windowlist can only
      // be invalidated from the main-thread (see OnNavigation)
      LOG(("Returning success for getUserMedia()"));
      mOnSuccess->OnSuccess(aStream);
    }
    uint64_t mWindowID;
    nsCOMPtr<nsIDOMGetUserMediaSuccessCallback> mOnSuccess;
    nsRefPtr<MediaManager> mManager;
    // Keep the DOMMediaStream alive until the NotifyTracksAvailable callback
    // has fired, otherwise we might immediately destroy the DOMMediaStream and
    // shut down the underlying MediaStream prematurely.
    // This creates a cycle which is broken when NotifyTracksAvailable
    // is fired (which will happen unless the browser shuts down,
    // since we only add this callback when we've successfully appended
    // the desired tracks in the MediaStreamGraph) or when
    // DOMMediaStream::NotifyMediaStreamGraphShutdown is called.
    nsRefPtr<DOMMediaStream> mStream;
  };

  NS_IMETHOD
  Run()
  {
#ifdef MOZ_WEBRTC
    int32_t aec = (int32_t) webrtc::kEcUnchanged;
    int32_t agc = (int32_t) webrtc::kAgcUnchanged;
    int32_t noise = (int32_t) webrtc::kNsUnchanged;
#else
    int32_t aec = 0, agc = 0, noise = 0;
#endif
    bool aec_on = false, agc_on = false, noise_on = false;
    int32_t playout_delay = 0;

    NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
    nsPIDOMWindow *window = static_cast<nsPIDOMWindow*>
      (nsGlobalWindow::GetInnerWindowWithId(mWindowID));

    // We're on main-thread, and the windowlist can only
    // be invalidated from the main-thread (see OnNavigation)
    StreamListeners* listeners = mManager->GetWindowListeners(mWindowID);
    if (!listeners || !window || !window->GetExtantDoc()) {
      // This window is no longer live.  mListener has already been removed
      return NS_OK;
    }

#ifdef MOZ_WEBRTC
    // Right now these configs are only of use if webrtc is available
    nsresult rv;
    nsCOMPtr<nsIPrefService> prefs = do_GetService("@mozilla.org/preferences-service;1", &rv);
    if (NS_SUCCEEDED(rv)) {
      nsCOMPtr<nsIPrefBranch> branch = do_QueryInterface(prefs);

      if (branch) {
        branch->GetBoolPref("media.getusermedia.aec_enabled", &aec_on);
        branch->GetIntPref("media.getusermedia.aec", &aec);
        branch->GetBoolPref("media.getusermedia.agc_enabled", &agc_on);
        branch->GetIntPref("media.getusermedia.agc", &agc);
        branch->GetBoolPref("media.getusermedia.noise_enabled", &noise_on);
        branch->GetIntPref("media.getusermedia.noise", &noise);
        branch->GetIntPref("media.getusermedia.playout_delay", &playout_delay);
      }
    }
#endif

    MediaStreamGraph::GraphDriverType graphDriverType =
      mAudioSource ? MediaStreamGraph::AUDIO_THREAD_DRIVER
                   : MediaStreamGraph::SYSTEM_THREAD_DRIVER;
    MediaStreamGraph* msg =
      MediaStreamGraph::GetInstance(graphDriverType,
                                    dom::AudioChannel::Normal);

    nsRefPtr<SourceMediaStream> stream = msg->CreateSourceStream(nullptr);

    nsRefPtr<DOMLocalMediaStream> domStream;
    // AudioCapture is a special case, here, in the sense that we're not really
    // using the audio source and the SourceMediaStream, which acts as
    // placeholders. We re-route a number of stream internaly in the MSG and mix
    // them down instead.
    if (mAudioSource &&
        mAudioSource->GetMediaSource() == dom::MediaSourceEnum::AudioCapture) {
      domStream = DOMLocalMediaStream::CreateAudioCaptureStream(window, msg);
      // It should be possible to pipe the capture stream to anything. CORS is
      // not a problem here, we got explicit user content.
      domStream->SetPrincipal(window->GetExtantDoc()->NodePrincipal());
      msg->RegisterCaptureStreamForWindow(
            mWindowID, domStream->GetStream()->AsProcessedStream());
      window->SetAudioCapture(true);
    } else {
      // Normal case, connect the source stream to the track union stream to
      // avoid us blocking
      nsRefPtr<nsDOMUserMediaStream> trackunion =
        nsDOMUserMediaStream::CreateTrackUnionStream(window, mListener,
                                                     mAudioSource, mVideoSource,
                                                     msg);
      trackunion->GetStream()->AsProcessedStream()->SetAutofinish(true);
      nsRefPtr<MediaInputPort> port = trackunion->GetStream()->AsProcessedStream()->
        AllocateInputPort(stream);
      trackunion->mSourceStream = stream;
      trackunion->mPort = port.forget();
      // Log the relationship between SourceMediaStream and TrackUnion stream
      // Make sure logger starts before capture
      AsyncLatencyLogger::Get(true);
      LogLatency(AsyncLatencyLogger::MediaStreamCreate,
          reinterpret_cast<uint64_t>(stream.get()),
          reinterpret_cast<int64_t>(trackunion->GetStream()));

      nsCOMPtr<nsIPrincipal> principal;
      if (mPeerIdentity) {
        principal = nsNullPrincipal::Create();
        trackunion->SetPeerIdentity(mPeerIdentity.forget());
      } else {
        principal = window->GetExtantDoc()->NodePrincipal();
      }
      trackunion->CombineWithPrincipal(principal);

      domStream = trackunion.forget();
    }

    if (!domStream || sInShutdown) {
      nsCOMPtr<nsIDOMGetUserMediaErrorCallback> onFailure = mOnFailure.forget();
      LOG(("Returning error for getUserMedia() - no stream"));

      nsGlobalWindow* window = nsGlobalWindow::GetInnerWindowWithId(mWindowID);
      if (window) {
        nsRefPtr<MediaStreamError> error = new MediaStreamError(window,
            NS_LITERAL_STRING("InternalError"),
            sInShutdown ? NS_LITERAL_STRING("In shutdown") :
                          NS_LITERAL_STRING("No stream."));
        onFailure->OnError(error);
      }
      return NS_OK;
    }

    // The listener was added at the beginning in an inactive state.
    // Activate our listener. We'll call Start() on the source when get a callback
    // that the MediaStream has started consuming. The listener is freed
    // when the page is invalidated (on navigation or close).
    mListener->Activate(stream.forget(), mAudioSource, mVideoSource);

    // Note: includes JS callbacks; must be released on MainThread
    TracksAvailableCallback* tracksAvailableCallback =
      new TracksAvailableCallback(mManager, mOnSuccess, mWindowID, domStream);

    mListener->AudioConfig(aec_on, (uint32_t) aec,
                           agc_on, (uint32_t) agc,
                           noise_on, (uint32_t) noise,
                           playout_delay);

    // Dispatch to the media thread to ask it to start the sources,
    // because that can take a while.
    // Pass ownership of trackunion to the MediaOperationTask
    // to ensure it's kept alive until the MediaOperationTask runs (at least).
    MediaManager::PostTask(
      FROM_HERE, new MediaOperationTask(MEDIA_START, mListener, domStream,
                                        tracksAvailableCallback, mAudioSource,
                                        mVideoSource, false, mWindowID,
                                        mOnFailure.forget()));
    // We won't need mOnFailure now.
    mOnFailure = nullptr;

    if (!MediaManager::IsPrivateBrowsing(window)) {
      // Call GetOriginKey again, this time w/persist = true, to promote
      // deviceIds to persistent, in case they're not already. Fire'n'forget.
      nsRefPtr<Pledge<nsCString>> p = media::GetOriginKey(mOrigin, false, true);
    }
    return NS_OK;
  }

private:
  nsCOMPtr<nsIDOMGetUserMediaSuccessCallback> mOnSuccess;
  nsCOMPtr<nsIDOMGetUserMediaErrorCallback> mOnFailure;
  nsRefPtr<MediaEngineSource> mAudioSource;
  nsRefPtr<MediaEngineSource> mVideoSource;
  uint64_t mWindowID;
  nsRefPtr<GetUserMediaCallbackMediaStreamListener> mListener;
  nsCString mOrigin;
  nsAutoPtr<PeerIdentity> mPeerIdentity;
  nsRefPtr<MediaManager> mManager; // get ref to this when creating the runnable
};

static bool
IsOn(const OwningBooleanOrMediaTrackConstraints &aUnion) {
  return !aUnion.IsBoolean() || aUnion.GetAsBoolean();
}

static const MediaTrackConstraints&
GetInvariant(const OwningBooleanOrMediaTrackConstraints &aUnion) {
  static const MediaTrackConstraints empty;
  return aUnion.IsMediaTrackConstraints() ?
      aUnion.GetAsMediaTrackConstraints() : empty;
}

// Source getter returning full list

template<class DeviceType>
static void
GetSources(MediaEngine *engine, dom::MediaSourceEnum aSrcType,
           void (MediaEngine::* aEnumerate)(dom::MediaSourceEnum,
               nsTArray<nsRefPtr<typename DeviceType::Source> >*),
           nsTArray<nsRefPtr<DeviceType>>& aResult,
           const char* media_device_name = nullptr)
{
  nsTArray<nsRefPtr<typename DeviceType::Source>> sources;

  (engine->*aEnumerate)(aSrcType, &sources);
  /**
    * We're allowing multiple tabs to access the same camera for parity
    * with Chrome.  See bug 811757 for some of the issues surrounding
    * this decision.  To disallow, we'd filter by IsAvailable() as we used
    * to.
    */
  if (media_device_name && *media_device_name)  {
    for (auto& source : sources) {
      nsString deviceName;
      source->GetName(deviceName);
      if (deviceName.EqualsASCII(media_device_name)) {
        aResult.AppendElement(new DeviceType(source));
        break;
      }
    }
  } else {
    for (auto& source : sources) {
      aResult.AppendElement(new DeviceType(source));
    }
  }
}

// Apply constrains to a supplied list of sources (removes items from the list)

template<class DeviceType>
static void
ApplyConstraints(const MediaTrackConstraints &aConstraints,
                 nsTArray<nsRefPtr<DeviceType>>& aSources)
{
  auto& c = aConstraints;

  // First apply top-level constraints.

  // Stack constraintSets that pass, starting with the required one, because the
  // whole stack must be re-satisfied each time a capability-set is ruled out
  // (this avoids storing state or pushing algorithm into the lower-level code).
  nsTArray<const MediaTrackConstraintSet*> aggregateConstraints;
  aggregateConstraints.AppendElement(&c);

  std::multimap<uint32_t, nsRefPtr<DeviceType>> ordered;

  for (uint32_t i = 0; i < aSources.Length();) {
    uint32_t distance = aSources[i]->GetBestFitnessDistance(aggregateConstraints);
    if (distance == UINT32_MAX) {
      aSources.RemoveElementAt(i);
    } else {
      ordered.insert(std::pair<uint32_t, nsRefPtr<DeviceType>>(distance,
                                                               aSources[i]));
      ++i;
    }
  }
  // Order devices by shortest distance
  for (auto& ordinal : ordered) {
    aSources.RemoveElement(ordinal.second);
    aSources.AppendElement(ordinal.second);
  }

  // Then apply advanced constraints.

  if (c.mAdvanced.WasPassed()) {
    auto &array = c.mAdvanced.Value();

    for (int i = 0; i < int(array.Length()); i++) {
      aggregateConstraints.AppendElement(&array[i]);
      nsTArray<nsRefPtr<DeviceType>> rejects;
      for (uint32_t j = 0; j < aSources.Length();) {
        if (aSources[j]->GetBestFitnessDistance(aggregateConstraints) == UINT32_MAX) {
          rejects.AppendElement(aSources[j]);
          aSources.RemoveElementAt(j);
        } else {
          ++j;
        }
      }
      if (!aSources.Length()) {
        aSources.AppendElements(Move(rejects));
        aggregateConstraints.RemoveElementAt(aggregateConstraints.Length() - 1);
      }
    }
  }
}

static bool
ApplyConstraints(MediaStreamConstraints &aConstraints,
                 nsTArray<nsRefPtr<MediaDevice>>& aSources)
{
  // Since the advanced part of the constraints algorithm needs to know when
  // a candidate set is overconstrained (zero members), we must split up the
  // list into videos and audios, and put it back together again at the end.

  bool overconstrained = false;
  nsTArray<nsRefPtr<VideoDevice>> videos;
  nsTArray<nsRefPtr<AudioDevice>> audios;

  for (auto& source : aSources) {
    if (source->mIsVideo) {
      nsRefPtr<VideoDevice> video = static_cast<VideoDevice*>(source.get());
      videos.AppendElement(video);
    } else {
      nsRefPtr<AudioDevice> audio = static_cast<AudioDevice*>(source.get());
      audios.AppendElement(audio);
    }
  }
  aSources.Clear();
  MOZ_ASSERT(!aSources.Length());

  if (IsOn(aConstraints.mVideo)) {
    ApplyConstraints(GetInvariant(aConstraints.mVideo), videos);
    if (!videos.Length()) {
      overconstrained = true;
    }
    for (auto& video : videos) {
      aSources.AppendElement(video);
    }
  }
  if (IsOn(aConstraints.mAudio)) {
    ApplyConstraints(GetInvariant(aConstraints.mAudio), audios);
    if (!audios.Length()) {
      overconstrained = true;
    }
    for (auto& audio : audios) {
      aSources.AppendElement(audio);
    }
  }
  return !overconstrained;
}

/**
 * Runs on a seperate thread and is responsible for enumerating devices.
 * Depending on whether a picture or stream was asked for, either
 * ProcessGetUserMedia is called, and the results are sent back to the DOM.
 *
 * Do not run this on the main thread. The success and error callbacks *MUST*
 * be dispatched on the main thread!
 */
class GetUserMediaTask : public Task
{
public:
  GetUserMediaTask(
    const MediaStreamConstraints& aConstraints,
    already_AddRefed<nsIDOMGetUserMediaSuccessCallback> aOnSuccess,
    already_AddRefed<nsIDOMGetUserMediaErrorCallback> aOnFailure,
    uint64_t aWindowID, GetUserMediaCallbackMediaStreamListener *aListener,
    MediaEnginePrefs &aPrefs,
    const nsCString& aOrigin,
    MediaManager::SourceSet* aSourceSet)
    : mConstraints(aConstraints)
    , mOnSuccess(aOnSuccess)
    , mOnFailure(aOnFailure)
    , mWindowID(aWindowID)
    , mListener(aListener)
    , mPrefs(aPrefs)
    , mOrigin(aOrigin)
    , mDeviceChosen(false)
    , mSourceSet(aSourceSet)
    , mManager(MediaManager::GetInstance())
  {}

  ~GetUserMediaTask() {
  }

  void
  Fail(const nsAString& aName, const nsAString& aMessage = EmptyString()) {
    nsRefPtr<MediaMgrError> error = new MediaMgrError(aName, aMessage);
    nsRefPtr<ErrorCallbackRunnable<nsIDOMGetUserMediaSuccessCallback>> runnable =
      new ErrorCallbackRunnable<nsIDOMGetUserMediaSuccessCallback>(mOnSuccess,
                                                                   mOnFailure,
                                                                   *error,
                                                                   mWindowID);
    // These should be empty now
    MOZ_ASSERT(!mOnSuccess);
    MOZ_ASSERT(!mOnFailure);

    NS_DispatchToMainThread(runnable.forget());
    // Do after ErrorCallbackRunnable Run()s, as it checks active window list
    NS_DispatchToMainThread(do_AddRef(new GetUserMediaListenerRemove(mWindowID, mListener)));
  }

  void
  Run()
  {
    MOZ_ASSERT(!NS_IsMainThread());
    MOZ_ASSERT(mOnSuccess);
    MOZ_ASSERT(mOnFailure);
    MOZ_ASSERT(mDeviceChosen);

    // Allocate a video or audio device and return a MediaStream via
    // a GetUserMediaStreamRunnable.

    nsresult rv;

    if (mAudioDevice) {
      rv = mAudioDevice->Allocate(GetInvariant(mConstraints.mAudio), mPrefs);
      if (NS_FAILED(rv)) {
        LOG(("Failed to allocate audiosource %d",rv));
        Fail(NS_LITERAL_STRING("SourceUnavailableError"),
             NS_LITERAL_STRING("Failed to allocate audiosource"));
        return;
      }
    }
    if (mVideoDevice) {
      rv = mVideoDevice->Allocate(GetInvariant(mConstraints.mVideo), mPrefs);
      if (NS_FAILED(rv)) {
        LOG(("Failed to allocate videosource %d\n",rv));
        if (mAudioDevice) {
          mAudioDevice->GetSource()->Deallocate();
        }
        Fail(NS_LITERAL_STRING("SourceUnavailableError"),
             NS_LITERAL_STRING("Failed to allocate videosource"));
        return;
      }
    }
    PeerIdentity* peerIdentity = nullptr;
    if (!mConstraints.mPeerIdentity.IsEmpty()) {
      peerIdentity = new PeerIdentity(mConstraints.mPeerIdentity);
    }

    NS_DispatchToMainThread(do_AddRef(new GetUserMediaStreamRunnable(
      mOnSuccess, mOnFailure, mWindowID, mListener, mOrigin,
      (mAudioDevice? mAudioDevice->GetSource() : nullptr),
      (mVideoDevice? mVideoDevice->GetSource() : nullptr),
      peerIdentity
    )));

    MOZ_ASSERT(!mOnSuccess);
    MOZ_ASSERT(!mOnFailure);
  }

  nsresult
  Denied(const nsAString& aName,
         const nsAString& aMessage = EmptyString())
  {
    MOZ_ASSERT(mOnSuccess);
    MOZ_ASSERT(mOnFailure);

    // We add a disabled listener to the StreamListeners array until accepted
    // If this was the only active MediaStream, remove the window from the list.
    if (NS_IsMainThread()) {
      // This is safe since we're on main-thread, and the window can only
      // be invalidated from the main-thread (see OnNavigation)
      nsCOMPtr<nsIDOMGetUserMediaSuccessCallback> onSuccess = mOnSuccess.forget();
      nsCOMPtr<nsIDOMGetUserMediaErrorCallback> onFailure = mOnFailure.forget();

      nsGlobalWindow* window = nsGlobalWindow::GetInnerWindowWithId(mWindowID);
      if (window) {
        nsRefPtr<MediaStreamError> error = new MediaStreamError(window,
                                                                aName, aMessage);
        onFailure->OnError(error);
      }
      // Should happen *after* error runs for consistency, but may not matter
      nsRefPtr<MediaManager> manager(MediaManager::GetInstance());
      manager->RemoveFromWindowList(mWindowID, mListener);
    } else {
      // This will re-check the window being alive on main-thread
      // and remove the listener on MainThread as well
      Fail(aName, aMessage);
    }

    MOZ_ASSERT(!mOnSuccess);
    MOZ_ASSERT(!mOnFailure);

    return NS_OK;
  }

  nsresult
  SetContraints(const MediaStreamConstraints& aConstraints)
  {
    mConstraints = aConstraints;
    return NS_OK;
  }

  nsresult
  SetAudioDevice(AudioDevice* aAudioDevice)
  {
    mAudioDevice = aAudioDevice;
    mDeviceChosen = true;
    return NS_OK;
  }

  nsresult
  SetVideoDevice(VideoDevice* aVideoDevice)
  {
    mVideoDevice = aVideoDevice;
    mDeviceChosen = true;
    return NS_OK;
  }

private:
  MediaStreamConstraints mConstraints;

  nsCOMPtr<nsIDOMGetUserMediaSuccessCallback> mOnSuccess;
  nsCOMPtr<nsIDOMGetUserMediaErrorCallback> mOnFailure;
  uint64_t mWindowID;
  nsRefPtr<GetUserMediaCallbackMediaStreamListener> mListener;
  nsRefPtr<AudioDevice> mAudioDevice;
  nsRefPtr<VideoDevice> mVideoDevice;
  MediaEnginePrefs mPrefs;
  nsCString mOrigin;

  bool mDeviceChosen;
public:
  nsAutoPtr<MediaManager::SourceSet> mSourceSet;
private:
  nsRefPtr<MediaManager> mManager; // get ref to this when creating the runnable
};

#if defined(ANDROID) && !defined(MOZ_WIDGET_GONK)
class GetUserMediaRunnableWrapper : public nsRunnable
{
public:
  // This object must take ownership of task
  GetUserMediaRunnableWrapper(GetUserMediaTask* task) :
    mTask(task) {
  }

  ~GetUserMediaRunnableWrapper() {
  }

  NS_IMETHOD Run() {
    mTask->Run();
    return NS_OK;
  }

private:
  nsAutoPtr<GetUserMediaTask> mTask;
};
#endif

// TODO: Remove once upgraded to GCC 4.8+ on linux. Bogus error on static func:
// error: 'this' was not captured for this lambda function

static auto& MediaManager_GetInstance = MediaManager::GetInstance;
static auto& MediaManager_ToJSArray = MediaManager::ToJSArray;
static auto& MediaManager_AnonymizeDevices = MediaManager::AnonymizeDevices;

/**
 * EnumerateRawDevices - Enumerate a list of audio & video devices that
 * satisfy passed-in constraints. List contains raw id's.
 */

already_AddRefed<MediaManager::PledgeSourceSet>
MediaManager::EnumerateRawDevices(uint64_t aWindowId,
                                  MediaSourceEnum aVideoType,
                                  MediaSourceEnum aAudioType,
                                  bool aFake, bool aFakeTracks)
{
  MOZ_ASSERT(NS_IsMainThread());
  nsRefPtr<PledgeSourceSet> p = new PledgeSourceSet();
  uint32_t id = mOutstandingPledges.Append(*p);

  // Check if the preference for using audio/video loopback devices is
  // enabled. This is currently used for automated media tests only.
  //
  // If present (and we're doing non-exotic cameras and microphones) use them
  // instead of our built-in fake devices, except if fake tracks are requested
  // (a feature of the built-in ones only).

  nsAdoptingCString audioLoopDev, videoLoopDev;
  if (!aFakeTracks) {
    if (aVideoType == dom::MediaSourceEnum::Camera) {
      audioLoopDev = Preferences::GetCString("media.audio_loopback_dev");
      videoLoopDev = Preferences::GetCString("media.video_loopback_dev");

      if (aFake && !audioLoopDev.IsEmpty() && !videoLoopDev.IsEmpty()) {
        aFake = false;
      }
    } else {
      aFake = false;
    }
  }

  MediaManager::PostTask(FROM_HERE, NewTaskFrom([id, aWindowId, audioLoopDev,
                                                 videoLoopDev, aVideoType,
                                                 aAudioType, aFake,
                                                 aFakeTracks]() mutable {
    nsRefPtr<MediaEngine> backend;
    if (aFake) {
      backend = new MediaEngineDefault(aFakeTracks);
    } else {
      nsRefPtr<MediaManager> manager = MediaManager_GetInstance();
      backend = manager->GetBackend(aWindowId);
    }

    ScopedDeletePtr<SourceSet> result(new SourceSet);

    nsTArray<nsRefPtr<VideoDevice>> videos;
    GetSources(backend, aVideoType, &MediaEngine::EnumerateVideoDevices, videos,
               videoLoopDev);
    for (auto& source : videos) {
      result->AppendElement(source);
    }

    nsTArray<nsRefPtr<AudioDevice>> audios;
    GetSources(backend, aAudioType,
               &MediaEngine::EnumerateAudioDevices, audios, audioLoopDev);
    for (auto& source : audios) {
      result->AppendElement(source);
    }

    SourceSet* handoff = result.forget();
    NS_DispatchToMainThread(do_AddRef(NewRunnableFrom([id, handoff]() mutable {
      ScopedDeletePtr<SourceSet> result(handoff); // grab result
      nsRefPtr<MediaManager> mgr = MediaManager_GetInstance();
      if (!mgr) {
        return NS_OK;
      }
      nsRefPtr<PledgeSourceSet> p = mgr->mOutstandingPledges.Remove(id);
      if (p) {
        p->Resolve(result.forget());
      }
      return NS_OK;
          })));
  }));
  return p.forget();
}

MediaManager::MediaManager()
  : mMediaThread(nullptr)
  , mMutex("mozilla::MediaManager")
  , mBackend(nullptr) {
  mPrefs.mWidth  = 0; // adaptive default
  mPrefs.mHeight = 0; // adaptive default
  mPrefs.mFPS    = MediaEngine::DEFAULT_VIDEO_FPS;
  mPrefs.mMinFPS = MediaEngine::DEFAULT_VIDEO_MIN_FPS;
  nsresult rv;
  nsCOMPtr<nsIPrefService> prefs = do_GetService("@mozilla.org/preferences-service;1", &rv);
  if (NS_SUCCEEDED(rv)) {
    nsCOMPtr<nsIPrefBranch> branch = do_QueryInterface(prefs);
    if (branch) {
      GetPrefs(branch, nullptr);
    }
  }
  LOG(("%s: default prefs: %dx%d @%dfps (min %d)", __FUNCTION__,
       mPrefs.mWidth, mPrefs.mHeight, mPrefs.mFPS, mPrefs.mMinFPS));
}

NS_IMPL_ISUPPORTS(MediaManager, nsIMediaManagerService, nsIObserver)

/* static */ StaticRefPtr<MediaManager> MediaManager::sSingleton;

#ifdef DEBUG
/* static */ bool
MediaManager::IsInMediaThread()
{
  return sSingleton?
      (sSingleton->mMediaThread->thread_id() == PlatformThread::CurrentId()) :
      false;
}
#endif

// NOTE: never Dispatch(....,NS_DISPATCH_SYNC) to the MediaManager
// thread from the MainThread, as we NS_DISPATCH_SYNC to MainThread
// from MediaManager thread.

// Guaranteed never to return nullptr.
/* static */  MediaManager*
MediaManager::Get() {
  if (!sSingleton) {
    NS_ASSERTION(NS_IsMainThread(), "Only create MediaManager on main thread");
#ifdef DEBUG
    static int timesCreated = 0;
    timesCreated++;
    MOZ_ASSERT(timesCreated == 1);
#endif
    sSingleton = new MediaManager();

    sSingleton->mMediaThread = new base::Thread("MediaManager");
    base::Thread::Options options;
#if defined(_WIN32)
    options.message_loop_type = MessageLoop::TYPE_MOZILLA_NONMAINUITHREAD;
#else
    options.message_loop_type = MessageLoop::TYPE_MOZILLA_NONMAINTHREAD;
#endif
    if (!sSingleton->mMediaThread->StartWithOptions(options)) {
      MOZ_CRASH();
    }

    LOG(("New Media thread for gum"));

    nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
    if (obs) {
      obs->AddObserver(sSingleton, "xpcom-will-shutdown", false);
      obs->AddObserver(sSingleton, "last-pb-context-exited", false);
      obs->AddObserver(sSingleton, "getUserMedia:privileged:allow", false);
      obs->AddObserver(sSingleton, "getUserMedia:response:allow", false);
      obs->AddObserver(sSingleton, "getUserMedia:response:deny", false);
      obs->AddObserver(sSingleton, "getUserMedia:revoke", false);
      obs->AddObserver(sSingleton, "phone-state-changed", false);
    }
    // else MediaManager won't work properly and will leak (see bug 837874)
    nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
    if (prefs) {
      prefs->AddObserver("media.navigator.video.default_width", sSingleton, false);
      prefs->AddObserver("media.navigator.video.default_height", sSingleton, false);
      prefs->AddObserver("media.navigator.video.default_fps", sSingleton, false);
      prefs->AddObserver("media.navigator.video.default_minfps", sSingleton, false);
    }
#ifdef MOZ_B2G
    // Init MediaPermissionManager before sending out any permission requests.
    (void) MediaPermissionManager::GetInstance();
#endif //MOZ_B2G
  }
  return sSingleton;
}

/* static */  MediaManager*
MediaManager::GetIfExists() {
  return sSingleton;
}

/* static */ already_AddRefed<MediaManager>
MediaManager::GetInstance()
{
  // so we can have non-refcounted getters
  nsRefPtr<MediaManager> service = MediaManager::Get();
  return service.forget();
}

media::Parent<media::NonE10s>*
MediaManager::GetNonE10sParent()
{
  if (!mNonE10sParent) {
    mNonE10sParent = new media::Parent<media::NonE10s>(true);
  }
  return mNonE10sParent;
}

/* static */
void
MediaManager::PostTask(const tracked_objects::Location& from_here, Task* task)
{
  if (sInShutdown) {
    // Can't safely delete task here since it may have items with specific
    // thread-release requirements.
    return;
  }
  NS_ASSERTION(Get(), "MediaManager singleton?");
  NS_ASSERTION(Get()->mMediaThread, "No thread yet");
  Get()->mMediaThread->message_loop()->PostTask(from_here, task);
}

/* static */ nsresult
MediaManager::NotifyRecordingStatusChange(nsPIDOMWindow* aWindow,
                                          const nsString& aMsg,
                                          const bool& aIsAudio,
                                          const bool& aIsVideo)
{
  NS_ENSURE_ARG(aWindow);

  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
  if (!obs) {
    NS_WARNING("Could not get the Observer service for GetUserMedia recording notification.");
    return NS_ERROR_FAILURE;
  }

  nsRefPtr<nsHashPropertyBag> props = new nsHashPropertyBag();
  props->SetPropertyAsBool(NS_LITERAL_STRING("isAudio"), aIsAudio);
  props->SetPropertyAsBool(NS_LITERAL_STRING("isVideo"), aIsVideo);

  bool isApp = false;
  nsString requestURL;

  if (nsCOMPtr<nsIDocShell> docShell = aWindow->GetDocShell()) {
    nsresult rv = docShell->GetIsApp(&isApp);
    NS_ENSURE_SUCCESS(rv, rv);

    if (isApp) {
      rv = docShell->GetAppManifestURL(requestURL);
      NS_ENSURE_SUCCESS(rv, rv);
    }
  }

  if (!isApp) {
    nsCString pageURL;
    nsCOMPtr<nsIURI> docURI = aWindow->GetDocumentURI();
    NS_ENSURE_TRUE(docURI, NS_ERROR_FAILURE);

    nsresult rv = docURI->GetSpec(pageURL);
    NS_ENSURE_SUCCESS(rv, rv);

    requestURL = NS_ConvertUTF8toUTF16(pageURL);
  }

  props->SetPropertyAsBool(NS_LITERAL_STRING("isApp"), isApp);
  props->SetPropertyAsAString(NS_LITERAL_STRING("requestURL"), requestURL);

  obs->NotifyObservers(static_cast<nsIPropertyBag2*>(props),
                       "recording-device-events",
                       aMsg.get());

  // Forward recording events to parent process.
  // The events are gathered in chrome process and used for recording indicator
  if (!XRE_IsParentProcess()) {
    unused <<
      dom::ContentChild::GetSingleton()->SendRecordingDeviceEvents(aMsg,
                                                                   requestURL,
                                                                   aIsAudio,
                                                                   aIsVideo);
  }

  return NS_OK;
}

bool MediaManager::IsPrivileged()
{
  bool permission = nsContentUtils::IsCallerChrome();

  // Developer preference for turning off permission check.
  if (Preferences::GetBool("media.navigator.permission.disabled", false)) {
    permission = true;
  }
  return permission;
}

bool MediaManager::IsLoop(nsIURI* aDocURI)
{
  MOZ_ASSERT(aDocURI);

  nsCOMPtr<nsIURI> loopURI;
  nsresult rv = NS_NewURI(getter_AddRefs(loopURI), "about:loopconversation");
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return false;
  }
  bool result = false;
  rv = aDocURI->EqualsExceptRef(loopURI, &result);
  NS_ENSURE_SUCCESS(rv, false);
  return result;
}

bool MediaManager::IsPrivateBrowsing(nsPIDOMWindow *window)
{
  nsCOMPtr<nsIDocument> doc = window->GetDoc();
  nsCOMPtr<nsILoadContext> loadContext = doc->GetLoadContext();
  return loadContext && loadContext->UsePrivateBrowsing();
}

nsresult MediaManager::GenerateUUID(nsAString& aResult)
{
  nsresult rv;
  nsCOMPtr<nsIUUIDGenerator> uuidgen =
      do_GetService("@mozilla.org/uuid-generator;1", &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  // Generate a call ID.
  nsID id;
  rv = uuidgen->GenerateUUIDInPlace(&id);
  NS_ENSURE_SUCCESS(rv, rv);

  char buffer[NSID_LENGTH];
  id.ToProvidedString(buffer);
  aResult.Assign(NS_ConvertUTF8toUTF16(buffer));
  return NS_OK;
}

/**
 * The entry point for this file. A call from Navigator::mozGetUserMedia
 * will end up here. MediaManager is a singleton that is responsible
 * for handling all incoming getUserMedia calls from every window.
 */
nsresult
MediaManager::GetUserMedia(nsPIDOMWindow* aWindow,
                           const MediaStreamConstraints& aConstraintsPassedIn,
                           nsIDOMGetUserMediaSuccessCallback* aOnSuccess,
                           nsIDOMGetUserMediaErrorCallback* aOnFailure)
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aWindow);
  MOZ_ASSERT(aOnFailure);
  MOZ_ASSERT(aOnSuccess);
  nsCOMPtr<nsIDOMGetUserMediaSuccessCallback> onSuccess(aOnSuccess);
  nsCOMPtr<nsIDOMGetUserMediaErrorCallback> onFailure(aOnFailure);
  uint64_t windowID = aWindow->WindowID();

  MediaStreamConstraints c(aConstraintsPassedIn); // use a modifiable copy

  // Do all the validation we can while we're sync (to return an
  // already-rejected promise on failure).

  if (!IsOn(c.mVideo) && !IsOn(c.mAudio)) {
    nsRefPtr<MediaStreamError> error =
        new MediaStreamError(aWindow,
                             NS_LITERAL_STRING("NotSupportedError"),
                             NS_LITERAL_STRING("audio and/or video is required"));
    onFailure->OnError(error);
    return NS_OK;
  }
  if (sInShutdown) {
    nsRefPtr<MediaStreamError> error =
        new MediaStreamError(aWindow,
                             NS_LITERAL_STRING("AbortError"),
                             NS_LITERAL_STRING("In shutdown"));
    onFailure->OnError(error);
    return NS_OK;
  }

  // Determine permissions early (while we still have a stack).

  nsIURI* docURI = aWindow->GetDocumentURI();
  if (!docURI) {
    return NS_ERROR_UNEXPECTED;
  }
  bool loop = IsLoop(docURI);
  bool privileged = loop || IsPrivileged();
  bool isHTTPS = false;
  docURI->SchemeIs("https", &isHTTPS);

  nsCString origin;
  nsresult rv = nsPrincipal::GetOriginForURI(docURI, origin);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (!Preferences::GetBool("media.navigator.video.enabled", true)) {
    c.mVideo.SetAsBoolean() = false;
  }

  MediaSourceEnum videoType = dom::MediaSourceEnum::Camera;
  MediaSourceEnum audioType = dom::MediaSourceEnum::Microphone;

  if (c.mVideo.IsMediaTrackConstraints()) {
    auto& vc = c.mVideo.GetAsMediaTrackConstraints();
    videoType = StringToEnum(dom::MediaSourceEnumValues::strings,
                             vc.mMediaSource,
                             videoType);
    switch (videoType) {
      case dom::MediaSourceEnum::Camera:
        break;

      case dom::MediaSourceEnum::Browser:
      case dom::MediaSourceEnum::Screen:
      case dom::MediaSourceEnum::Application:
      case dom::MediaSourceEnum::Window:
        // Deny screensharing request if support is disabled, or
        // the requesting document is not from a host on the whitelist, or
        // we're on Mac OSX 10.6 and WinXP until proved that they work
        if (!Preferences::GetBool(((videoType == dom::MediaSourceEnum::Browser)?
                                   "media.getusermedia.browser.enabled" :
                                   "media.getusermedia.screensharing.enabled"),
                                  false) ||
#if defined(XP_MACOSX) || defined(XP_WIN)
            (
              // Allow tab sharing for all platforms including XP and OSX 10.6
              (videoType != dom::MediaSourceEnum::Browser) &&
              !Preferences::GetBool("media.getusermedia.screensharing.allow_on_old_platforms",
                                    false) &&
#if defined(XP_MACOSX)
              !nsCocoaFeatures::OnLionOrLater()
#endif
#if defined (XP_WIN)
              !IsVistaOrLater()
#endif
              ) ||
#endif
            (!privileged && !HostHasPermission(*docURI))) {
          nsRefPtr<MediaStreamError> error =
              new MediaStreamError(aWindow,
                                   NS_LITERAL_STRING("PermissionDeniedError"));
          onFailure->OnError(error);
          return NS_OK;
        }
        break;

      case dom::MediaSourceEnum::Microphone:
      case dom::MediaSourceEnum::Other:
      default: {
        nsRefPtr<MediaStreamError> error =
            new MediaStreamError(aWindow, NS_LITERAL_STRING("NotFoundError"));
        onFailure->OnError(error);
        return NS_OK;
      }
    }

    if (vc.mAdvanced.WasPassed() && videoType != dom::MediaSourceEnum::Camera) {
      // iterate through advanced, forcing all unset mediaSources to match "root"
      const char *unset = EnumToASCII(dom::MediaSourceEnumValues::strings,
                                      dom::MediaSourceEnum::Camera);
      for (MediaTrackConstraintSet& cs : vc.mAdvanced.Value()) {
        if (cs.mMediaSource.EqualsASCII(unset)) {
          cs.mMediaSource = vc.mMediaSource;
        }
      }
    }
    if (!privileged) {
      // only allow privileged content to set the window id
      if (vc.mBrowserWindow.WasPassed()) {
        vc.mBrowserWindow.Value() = -1;
      }
      if (vc.mAdvanced.WasPassed()) {
        for (MediaTrackConstraintSet& cs : vc.mAdvanced.Value()) {
          if (cs.mBrowserWindow.WasPassed()) {
            cs.mBrowserWindow.Value() = -1;
          }
        }
      }
    }

    // For all but tab sharing, Loop needs to prompt as we are using the
    // permission menu for selection of the device currently. For tab sharing,
    // Loop has implicit permissions within Firefox, as it is built-in,
    // and will manage the active tab and provide appropriate UI.
    if (loop && (videoType == dom::MediaSourceEnum::Window ||
                 videoType == dom::MediaSourceEnum::Application ||
                 videoType == dom::MediaSourceEnum::Screen)) {
       privileged = false;
    }
  }

  if (c.mAudio.IsMediaTrackConstraints()) {
    auto& ac = c.mAudio.GetAsMediaTrackConstraints();
    audioType = StringToEnum(dom::MediaSourceEnumValues::strings,
                             ac.mMediaSource,
                             audioType);
    // Work around WebIDL default since spec uses same dictionary w/audio & video.
    if (audioType == dom::MediaSourceEnum::Camera) {
      audioType = dom::MediaSourceEnum::Microphone;
      ac.mMediaSource.AssignASCII(EnumToASCII(dom::MediaSourceEnumValues::strings,
                                              audioType));
    }

    switch (audioType) {
      case dom::MediaSourceEnum::Microphone:
        break;

      case dom::MediaSourceEnum::AudioCapture:
        // Only enable AudioCapture if the pref is enabled. If it's not, we can
        // deny right away.
        if (!Preferences::GetBool("media.getusermedia.audiocapture.enabled")) {
          nsRefPtr<MediaStreamError> error =
            new MediaStreamError(aWindow,
                                 NS_LITERAL_STRING("PermissionDeniedError"));
          onFailure->OnError(error);
          return NS_OK;
        }
        break;

      case dom::MediaSourceEnum::Other:
      default: {
        nsRefPtr<MediaStreamError> error =
            new MediaStreamError(aWindow, NS_LITERAL_STRING("NotFoundError"));
        onFailure->OnError(error);
        return NS_OK;
      }
    }
    if (ac.mAdvanced.WasPassed()) {
      // iterate through advanced, forcing all unset mediaSources to match "root"
      const char *unset = EnumToASCII(dom::MediaSourceEnumValues::strings,
                                      dom::MediaSourceEnum::Camera);
      for (MediaTrackConstraintSet& cs : ac.mAdvanced.Value()) {
        if (cs.mMediaSource.EqualsASCII(unset)) {
          cs.mMediaSource = ac.mMediaSource;
        }
      }
    }
  }
  StreamListeners* listeners = AddWindowID(windowID);

  // Create a disabled listener to act as a placeholder
  nsRefPtr<GetUserMediaCallbackMediaStreamListener> listener =
    new GetUserMediaCallbackMediaStreamListener(mMediaThread, windowID);

  // No need for locking because we always do this in the main thread.
  listeners->AppendElement(listener);

  if (!privileged) {
    // Check if this site has had persistent permissions denied.
    nsCOMPtr<nsIPermissionManager> permManager =
      do_GetService(NS_PERMISSIONMANAGER_CONTRACTID, &rv);
    NS_ENSURE_SUCCESS(rv, rv);

    uint32_t audioPerm = nsIPermissionManager::UNKNOWN_ACTION;
    if (IsOn(c.mAudio)) {
      rv = permManager->TestExactPermissionFromPrincipal(
        aWindow->GetExtantDoc()->NodePrincipal(), "microphone", &audioPerm);
      NS_ENSURE_SUCCESS(rv, rv);
    }

    uint32_t videoPerm = nsIPermissionManager::UNKNOWN_ACTION;
    if (IsOn(c.mVideo)) {
      rv = permManager->TestExactPermissionFromPrincipal(
        aWindow->GetExtantDoc()->NodePrincipal(), "camera", &videoPerm);
      NS_ENSURE_SUCCESS(rv, rv);
    }

    if ((!IsOn(c.mAudio) || audioPerm == nsIPermissionManager::DENY_ACTION) &&
        (!IsOn(c.mVideo) || videoPerm == nsIPermissionManager::DENY_ACTION)) {
      nsRefPtr<MediaStreamError> error =
          new MediaStreamError(aWindow, NS_LITERAL_STRING("PermissionDeniedError"));
      onFailure->OnError(error);
      RemoveFromWindowList(windowID, listener);
      return NS_OK;
    }
  }

#if defined(MOZ_B2G_CAMERA) && defined(MOZ_WIDGET_GONK)
  if (mCameraManager == nullptr) {
    mCameraManager = nsDOMCameraManager::CreateInstance(aWindow);
  }
#endif

  // Get list of all devices, with origin-specific device ids.

  MediaEnginePrefs prefs = mPrefs;

  nsString callID;
  rv = GenerateUUID(callID);
  NS_ENSURE_SUCCESS(rv, rv);

  bool fake = c.mFake.WasPassed()? c.mFake.Value() :
      Preferences::GetBool("media.navigator.streams.fake");

  bool fakeTracks = c.mFakeTracks.WasPassed()? c.mFakeTracks.Value() : false;

  bool askPermission = !privileged &&
      (!fake || Preferences::GetBool("media.navigator.permission.fake"));

  nsRefPtr<PledgeSourceSet> p = EnumerateDevicesImpl(windowID, videoType,
                                                     audioType, fake,
                                                     fakeTracks);
  p->Then([this, onSuccess, onFailure, windowID, c, listener, askPermission,
           prefs, isHTTPS, callID, origin](SourceSet*& aDevices) mutable {
    ScopedDeletePtr<SourceSet> devices(aDevices); // grab result

    // Ensure this pointer is still valid, and window is still alive.
    nsRefPtr<MediaManager> mgr = MediaManager::GetInstance();
    nsRefPtr<nsPIDOMWindow> window = static_cast<nsPIDOMWindow*>
        (nsGlobalWindow::GetInnerWindowWithId(windowID));
    if (!mgr || !window) {
      return;
    }

    // Apply any constraints. This modifies the list.

    if (!ApplyConstraints(c, *devices)) {
      nsRefPtr<MediaStreamError> error =
          new MediaStreamError(window, NS_LITERAL_STRING("NotFoundError"));
      onFailure->OnError(error);
      return;
    }

    nsCOMPtr<nsISupportsArray> devicesCopy; // before we give up devices below
    if (!askPermission) {
      nsresult rv = NS_NewISupportsArray(getter_AddRefs(devicesCopy));
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return;
      }
      for (auto& device : *devices) {
        rv = devicesCopy->AppendElement(device);
        if (NS_WARN_IF(NS_FAILED(rv))) {
          return;
        }
      }
    }

    // Pass callbacks and MediaStreamListener along to GetUserMediaTask.
    nsAutoPtr<GetUserMediaTask> task (new GetUserMediaTask(c, onSuccess.forget(),
                                                           onFailure.forget(),
                                                           windowID, listener,
                                                           prefs, origin,
                                                           devices.forget()));
    // Store the task w/callbacks.
    mActiveCallbacks.Put(callID, task.forget());

    // Add a WindowID cross-reference so OnNavigation can tear things down
    nsTArray<nsString>* array;
    if (!mCallIds.Get(windowID, &array)) {
      array = new nsTArray<nsString>();
      mCallIds.Put(windowID, array);
    }
    array->AppendElement(callID);

    nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
    if (!askPermission) {
      obs->NotifyObservers(devicesCopy, "getUserMedia:privileged:allow",
                           callID.BeginReading());
    } else {
      nsRefPtr<GetUserMediaRequest> req =
          new GetUserMediaRequest(window, callID, c, isHTTPS);
      obs->NotifyObservers(req, "getUserMedia:request", nullptr);
    }

#ifdef MOZ_WEBRTC
    EnableWebRtcLog();
#endif
  }, [onFailure](MediaStreamError& reason) mutable {
    onFailure->OnError(&reason);
  });
  return NS_OK;
}

/* static */ void
MediaManager::AnonymizeDevices(SourceSet& aDevices, const nsACString& aOriginKey)
{
  if (!aOriginKey.IsEmpty()) {
    for (auto& device : aDevices) {
      nsString id;
      device->GetId(id);
      AnonymizeId(id, aOriginKey);
      device->SetId(id);
    }
  }
}

/* static */ nsresult
MediaManager::AnonymizeId(nsAString& aId, const nsACString& aOriginKey)
{
  MOZ_ASSERT(NS_IsMainThread());

  nsresult rv;
  nsCOMPtr<nsIKeyObjectFactory> factory =
    do_GetService("@mozilla.org/security/keyobjectfactory;1", &rv);
  if (NS_FAILED(rv)) {
    return rv;
  }
  nsCString rawKey;
  rv = Base64Decode(aOriginKey, rawKey);
  if (NS_FAILED(rv)) {
    return rv;
  }
  nsCOMPtr<nsIKeyObject> key;
  rv = factory->KeyFromString(nsIKeyObject::HMAC, rawKey, getter_AddRefs(key));
  if (NS_FAILED(rv)) {
    return rv;
  }

  nsCOMPtr<nsICryptoHMAC> hasher =
    do_CreateInstance(NS_CRYPTO_HMAC_CONTRACTID, &rv);
  if (NS_FAILED(rv)) {
    return rv;
  }
  rv = hasher->Init(nsICryptoHMAC::SHA256, key);
  if (NS_FAILED(rv)) {
    return rv;
  }
  NS_ConvertUTF16toUTF8 id(aId);
  rv = hasher->Update(reinterpret_cast<const uint8_t*> (id.get()), id.Length());
  if (NS_FAILED(rv)) {
    return rv;
  }
  nsCString mac;
  rv = hasher->Finish(true, mac);
  if (NS_FAILED(rv)) {
    return rv;
  }

  aId = NS_ConvertUTF8toUTF16(mac);
  return NS_OK;
}

/* static */
already_AddRefed<nsIWritableVariant>
MediaManager::ToJSArray(SourceSet& aDevices)
{
  nsCOMPtr<nsIWritableVariant> var = do_CreateInstance("@mozilla.org/variant;1");
  size_t len = aDevices.Length();
  if (len) {
    nsTArray<nsIMediaDevice*> tmp(len);
    for (auto& device : aDevices) {
      tmp.AppendElement(device);
    }
    auto* elements = static_cast<const void*>(tmp.Elements());
    nsresult rv = var->SetAsArray(nsIDataType::VTYPE_INTERFACE,
                                  &NS_GET_IID(nsIMediaDevice), len,
                                  const_cast<void*>(elements));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return nullptr;
    }
  } else {
    var->SetAsEmptyArray(); // because SetAsArray() fails on zero length arrays.
  }
  return var.forget();
}

already_AddRefed<MediaManager::PledgeSourceSet>
MediaManager::EnumerateDevicesImpl(uint64_t aWindowId,
                                   MediaSourceEnum aVideoType,
                                   MediaSourceEnum aAudioType,
                                   bool aFake, bool aFakeTracks)
{
  MOZ_ASSERT(NS_IsMainThread());
  nsPIDOMWindow *window = static_cast<nsPIDOMWindow*>
      (nsGlobalWindow::GetInnerWindowWithId(aWindowId));

  // This function returns a pledge, a promise-like object with the future result
  nsRefPtr<PledgeSourceSet> pledge = new PledgeSourceSet();
  uint32_t id = mOutstandingPledges.Append(*pledge);

  // To get a device list anonymized for a particular origin, we must:
  // 1. Get an origin-key (for either regular or private browsing)
  // 2. Get the raw devices list
  // 3. Anonymize the raw list with the origin-key.

  bool privateBrowsing = IsPrivateBrowsing(window);
  nsCString origin;
  nsPrincipal::GetOriginForURI(window->GetDocumentURI(), origin);

  bool persist = IsActivelyCapturingOrHasAPermission(aWindowId);

  // GetOriginKey is an async API that returns a pledge (a promise-like
  // pattern). We use .Then() to pass in a lambda to run back on this same
  // thread later once GetOriginKey resolves. Needed variables are "captured"
  // (passed by value) safely into the lambda.

  nsRefPtr<Pledge<nsCString>> p = media::GetOriginKey(origin, privateBrowsing,
                                                      persist);
  p->Then([id, aWindowId, aVideoType, aAudioType,
           aFake, aFakeTracks](const nsCString& aOriginKey) mutable {
    MOZ_ASSERT(NS_IsMainThread());
    nsRefPtr<MediaManager> mgr = MediaManager_GetInstance();

    nsRefPtr<PledgeSourceSet> p = mgr->EnumerateRawDevices(aWindowId,
                                                           aVideoType, aAudioType,
                                                           aFake, aFakeTracks);
    p->Then([id, aWindowId, aOriginKey](SourceSet*& aDevices) mutable {
      ScopedDeletePtr<SourceSet> devices(aDevices); // secondary result

      // Only run if window is still on our active list.
      nsRefPtr<MediaManager> mgr = MediaManager_GetInstance();
      if (!mgr) {
        return NS_OK;
      }
      nsRefPtr<PledgeSourceSet> p = mgr->mOutstandingPledges.Remove(id);
      if (!p || !mgr->IsWindowStillActive(aWindowId)) {
        return NS_OK;
      }
      MediaManager_AnonymizeDevices(*devices, aOriginKey);
      p->Resolve(devices.forget());
      return NS_OK;
    });
  });
  return pledge.forget();
}

nsresult
MediaManager::EnumerateDevices(nsPIDOMWindow* aWindow,
                               nsIGetUserMediaDevicesSuccessCallback* aOnSuccess,
                               nsIDOMGetUserMediaErrorCallback* aOnFailure)
{
  MOZ_ASSERT(NS_IsMainThread());
  NS_ENSURE_TRUE(!sInShutdown, NS_ERROR_FAILURE);
  nsCOMPtr<nsIGetUserMediaDevicesSuccessCallback> onSuccess(aOnSuccess);
  nsCOMPtr<nsIDOMGetUserMediaErrorCallback> onFailure(aOnFailure);
  uint64_t windowId = aWindow->WindowID();

  StreamListeners* listeners = AddWindowID(windowId);

  // Create a disabled listener to act as a placeholder
  nsRefPtr<GetUserMediaCallbackMediaStreamListener> listener =
    new GetUserMediaCallbackMediaStreamListener(mMediaThread, windowId);

  // No need for locking because we always do this in the main thread.
  listeners->AppendElement(listener);

  bool fake = Preferences::GetBool("media.navigator.streams.fake");

  nsRefPtr<PledgeSourceSet> p = EnumerateDevicesImpl(windowId,
                                                     dom::MediaSourceEnum::Camera,
                                                     dom::MediaSourceEnum::Microphone,
                                                     fake);
  p->Then([onSuccess, windowId, listener](SourceSet*& aDevices) mutable {
    ScopedDeletePtr<SourceSet> devices(aDevices); // grab result
    nsRefPtr<MediaManager> mgr = MediaManager_GetInstance();
    mgr->RemoveFromWindowList(windowId, listener);
    nsCOMPtr<nsIWritableVariant> array = MediaManager_ToJSArray(*devices);
    onSuccess->OnSuccess(array);
  }, [onFailure, windowId, listener](MediaStreamError& reason) mutable {
    nsRefPtr<MediaManager> mgr = MediaManager_GetInstance();
    mgr->RemoveFromWindowList(windowId, listener);
    onFailure->OnError(&reason);
  });
  return NS_OK;
}

/*
 * GetUserMediaDevices - called by the UI-part of getUserMedia from chrome JS.
 */

nsresult
MediaManager::GetUserMediaDevices(nsPIDOMWindow* aWindow,
                                  const MediaStreamConstraints& aConstraints,
                                  nsIGetUserMediaDevicesSuccessCallback* aOnSuccess,
                                  nsIDOMGetUserMediaErrorCallback* aOnFailure,
                                  uint64_t aWindowId)
{
  MOZ_ASSERT(NS_IsMainThread());
  nsCOMPtr<nsIGetUserMediaDevicesSuccessCallback> onSuccess(aOnSuccess);
  nsCOMPtr<nsIDOMGetUserMediaErrorCallback> onFailure(aOnFailure);
  if (!aWindowId) {
    aWindowId = aWindow->WindowID();
  }

  // Ignore passed-in constraints, instead locate + return already-constrained list.

  nsTArray<nsString>* callIDs;
  if (!mCallIds.Get(aWindowId, &callIDs)) {
    return NS_ERROR_UNEXPECTED;
  }

  for (auto& callID : *callIDs) {
    GetUserMediaTask* task;
    if (mActiveCallbacks.Get(callID, &task)) {
      nsCOMPtr<nsIWritableVariant> array = MediaManager_ToJSArray(*task->mSourceSet);
      onSuccess->OnSuccess(array);
      return NS_OK;
    }
  }
  return NS_ERROR_UNEXPECTED;
}

MediaEngine*
MediaManager::GetBackend(uint64_t aWindowId)
{
  // Plugin backends as appropriate. The default engine also currently
  // includes picture support for Android.
  // This IS called off main-thread.
  MutexAutoLock lock(mMutex);
  if (!mBackend) {
    MOZ_RELEASE_ASSERT(!sInShutdown);  // we should never create a new backend in shutdown
#if defined(MOZ_WEBRTC)
    mBackend = new MediaEngineWebRTC(mPrefs);
#else
    mBackend = new MediaEngineDefault();
#endif
  }
  return mBackend;
}

static void
StopSharingCallback(MediaManager *aThis,
                    uint64_t aWindowID,
                    StreamListeners *aListeners,
                    void *aData)
{
  if (aListeners) {
    auto length = aListeners->Length();
    for (size_t i = 0; i < length; ++i) {
      GetUserMediaCallbackMediaStreamListener *listener = aListeners->ElementAt(i);

      if (listener->Stream()) { // aka HasBeenActivate()ed
        listener->Invalidate();
      }
      listener->Remove();
      listener->StopSharing();
    }
    aListeners->Clear();
    aThis->RemoveWindowID(aWindowID);
  }
}


void
MediaManager::OnNavigation(uint64_t aWindowID)
{
  NS_ASSERTION(NS_IsMainThread(), "OnNavigation called off main thread");
  LOG(("OnNavigation for %llu", aWindowID));

  // Invalidate this window. The runnables check this value before making
  // a call to content.

  nsTArray<nsString>* callIDs;
  if (mCallIds.Get(aWindowID, &callIDs)) {
    for (auto& callID : *callIDs) {
      mActiveCallbacks.Remove(callID);
    }
    mCallIds.Remove(aWindowID);
  }

  // This is safe since we're on main-thread, and the windowlist can only
  // be added to from the main-thread
  nsPIDOMWindow *window = static_cast<nsPIDOMWindow*>
      (nsGlobalWindow::GetInnerWindowWithId(aWindowID));
  if (window) {
    IterateWindowListeners(window, StopSharingCallback, nullptr);
  } else {
    RemoveWindowID(aWindowID);
  }
}

StreamListeners*
MediaManager::AddWindowID(uint64_t aWindowId)
{
  NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
  // Store the WindowID in a hash table and mark as active. The entry is removed
  // when this window is closed or navigated away from.
  // This is safe since we're on main-thread, and the windowlist can only
  // be invalidated from the main-thread (see OnNavigation)
  StreamListeners* listeners = GetActiveWindows()->Get(aWindowId);
  if (!listeners) {
    listeners = new StreamListeners;
    GetActiveWindows()->Put(aWindowId, listeners);
  }
  return listeners;
}

void
MediaManager::RemoveWindowID(uint64_t aWindowId)
{
  mActiveWindows.Remove(aWindowId);

  // get outer windowID
  nsPIDOMWindow *window = static_cast<nsPIDOMWindow*>
    (nsGlobalWindow::GetInnerWindowWithId(aWindowId));
  if (!window) {
    LOG(("No inner window for %llu", aWindowId));
    return;
  }

  nsPIDOMWindow *outer = window->GetOuterWindow();
  if (!outer) {
    LOG(("No outer window for inner %llu", aWindowId));
    return;
  }

  uint64_t outerID = outer->WindowID();

  // Notify the UI that this window no longer has gUM active
  char windowBuffer[32];
  PR_snprintf(windowBuffer, sizeof(windowBuffer), "%llu", outerID);
  nsString data = NS_ConvertUTF8toUTF16(windowBuffer);

  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
  obs->NotifyObservers(nullptr, "recording-window-ended", data.get());
  LOG(("Sent recording-window-ended for window %llu (outer %llu)",
       aWindowId, outerID));
}

void
MediaManager::RemoveFromWindowList(uint64_t aWindowID,
  GetUserMediaCallbackMediaStreamListener *aListener)
{
  NS_ASSERTION(NS_IsMainThread(), "RemoveFromWindowList called off main thread");

  // This is defined as safe on an inactive GUMCMSListener
  aListener->Remove(); // really queues the remove

  StreamListeners* listeners = GetWindowListeners(aWindowID);
  if (!listeners) {
    return;
  }
  listeners->RemoveElement(aListener);
  if (listeners->Length() == 0) {
    RemoveWindowID(aWindowID);
    // listeners has been deleted here
  }
}

void
MediaManager::GetPref(nsIPrefBranch *aBranch, const char *aPref,
                      const char *aData, int32_t *aVal)
{
  int32_t temp;
  if (aData == nullptr || strcmp(aPref,aData) == 0) {
    if (NS_SUCCEEDED(aBranch->GetIntPref(aPref, &temp))) {
      *aVal = temp;
    }
  }
}

void
MediaManager::GetPrefBool(nsIPrefBranch *aBranch, const char *aPref,
                          const char *aData, bool *aVal)
{
  bool temp;
  if (aData == nullptr || strcmp(aPref,aData) == 0) {
    if (NS_SUCCEEDED(aBranch->GetBoolPref(aPref, &temp))) {
      *aVal = temp;
    }
  }
}

void
MediaManager::GetPrefs(nsIPrefBranch *aBranch, const char *aData)
{
  GetPref(aBranch, "media.navigator.video.default_width", aData, &mPrefs.mWidth);
  GetPref(aBranch, "media.navigator.video.default_height", aData, &mPrefs.mHeight);
  GetPref(aBranch, "media.navigator.video.default_fps", aData, &mPrefs.mFPS);
  GetPref(aBranch, "media.navigator.video.default_minfps", aData, &mPrefs.mMinFPS);
}

nsresult
MediaManager::Observe(nsISupports* aSubject, const char* aTopic,
  const char16_t* aData)
{
  NS_ASSERTION(NS_IsMainThread(), "Observer invoked off the main thread");
  nsCOMPtr<nsIObserverService> obs = services::GetObserverService();

  if (!strcmp(aTopic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID)) {
    nsCOMPtr<nsIPrefBranch> branch( do_QueryInterface(aSubject) );
    if (branch) {
      GetPrefs(branch,NS_ConvertUTF16toUTF8(aData).get());
      LOG(("%s: %dx%d @%dfps (min %d)", __FUNCTION__,
           mPrefs.mWidth, mPrefs.mHeight, mPrefs.mFPS, mPrefs.mMinFPS));
    }
  } else if (!strcmp(aTopic, "xpcom-will-shutdown")) {
    sInShutdown = true;

    obs->RemoveObserver(this, "xpcom-will-shutdown");
    obs->RemoveObserver(this, "last-pb-context-exited");
    obs->RemoveObserver(this, "getUserMedia:privileged:allow");
    obs->RemoveObserver(this, "getUserMedia:response:allow");
    obs->RemoveObserver(this, "getUserMedia:response:deny");
    obs->RemoveObserver(this, "getUserMedia:revoke");

    nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
    if (prefs) {
      prefs->RemoveObserver("media.navigator.video.default_width", this);
      prefs->RemoveObserver("media.navigator.video.default_height", this);
      prefs->RemoveObserver("media.navigator.video.default_fps", this);
      prefs->RemoveObserver("media.navigator.video.default_minfps", this);
    }

    // Close off any remaining active windows.
    GetActiveWindows()->Clear();
    mActiveCallbacks.Clear();
    mCallIds.Clear();
    {
      MutexAutoLock lock(mMutex);
      if (mBackend) {
        mBackend->Shutdown(); // ok to invoke multiple times
      }
    }

    // Because mMediaThread is not an nsThread, we must dispatch to it so it can
    // clean up BackgroundChild. Continue stopping thread once this is done.

    class ShutdownTask : public Task
    {
    public:
      ShutdownTask(already_AddRefed<MediaEngine> aBackend,
                   nsRunnable* aReply)
        : mReply(aReply)
        , mBackend(aBackend) {}
    private:
      virtual void
      Run()
      {
        LOG(("MediaManager Thread Shutdown"));
        MOZ_ASSERT(MediaManager::IsInMediaThread());
        mozilla::ipc::BackgroundChild::CloseForCurrentThread();
        // must explicitly do this before dispatching the reply, since the reply may kill us with Stop()
        mBackend = nullptr; // last reference, will invoke Shutdown() again

        if (NS_FAILED(NS_DispatchToMainThread(mReply.forget()))) {
          LOG(("Will leak thread: DispatchToMainthread of reply runnable failed in MediaManager shutdown"));
        }
      }
      nsRefPtr<nsRunnable> mReply;
      RefPtr<MediaEngine> mBackend;
    };

    // Post ShutdownTask to execute on mMediaThread and pass in a lambda
    // callback to be executed back on this thread once it is done.
    //
    // The lambda callback "captures" the 'this' pointer for member access.
    // This is safe since this is guaranteed to be here since sSingleton isn't
    // cleared until the lambda function clears it.

    // note that this == sSingleton
    nsRefPtr<MediaManager> that(sSingleton);
    // Release the backend (and call Shutdown()) from within the MediaManager thread
    RefPtr<MediaEngine> temp;
    {
      MutexAutoLock lock(mMutex);
      temp = mBackend.forget();
    }
    // Don't use MediaManager::PostTask() because we're sInShutdown=true here!
    mMediaThread->message_loop()->PostTask(FROM_HERE, new ShutdownTask(
        temp.forget(),
        media::NewRunnableFrom([this, that]() mutable {
      LOG(("MediaManager shutdown lambda running, releasing MediaManager singleton and thread"));
      if (mMediaThread) {
        mMediaThread->Stop();
      }
      // we hold a ref to 'that' which is the same as sSingleton
      sSingleton = nullptr;

      return NS_OK;
    })));
    return NS_OK;

  } else if (!strcmp(aTopic, "last-pb-context-exited")) {
    // Clear memory of private-browsing-specific deviceIds. Fire and forget.
    media::SanitizeOriginKeys(0, true);
    return NS_OK;
  } else if (!strcmp(aTopic, "getUserMedia:privileged:allow") ||
             !strcmp(aTopic, "getUserMedia:response:allow")) {
    nsString key(aData);
    nsAutoPtr<GetUserMediaTask> task;
    mActiveCallbacks.RemoveAndForget(key, task);
    if (!task) {
      return NS_OK;
    }

    if (aSubject) {
      // A particular device or devices were chosen by the user.
      // NOTE: does not allow setting a device to null; assumes nullptr
      nsCOMPtr<nsISupportsArray> array(do_QueryInterface(aSubject));
      MOZ_ASSERT(array);
      uint32_t len = 0;
      array->Count(&len);
      if (!len) {
        // neither audio nor video were selected
        task->Denied(NS_LITERAL_STRING("PermissionDeniedError"));
        return NS_OK;
      }
      bool videoFound = false, audioFound = false;
      for (uint32_t i = 0; i < len; i++) {
        nsCOMPtr<nsISupports> supports;
        array->GetElementAt(i,getter_AddRefs(supports));
        nsCOMPtr<nsIMediaDevice> device(do_QueryInterface(supports));
        MOZ_ASSERT(device); // shouldn't be returning anything else...
        if (device) {
          nsString type;
          device->GetType(type);
          if (type.EqualsLiteral("video")) {
            if (!videoFound) {
              task->SetVideoDevice(static_cast<VideoDevice*>(device.get()));
              videoFound = true;
            }
          } else if (type.EqualsLiteral("audio")) {
            if (!audioFound) {
              task->SetAudioDevice(static_cast<AudioDevice*>(device.get()));
              audioFound = true;
            }
          } else {
            NS_WARNING("Unknown device type in getUserMedia");
          }
        }
      }
    }

    if (sInShutdown) {
      return task->Denied(NS_LITERAL_STRING("In shutdown"));
    }
    // Reuse the same thread to save memory.
    MediaManager::PostTask(FROM_HERE, task.forget());
    return NS_OK;

  } else if (!strcmp(aTopic, "getUserMedia:response:deny")) {
    nsString errorMessage(NS_LITERAL_STRING("PermissionDeniedError"));

    if (aSubject) {
      nsCOMPtr<nsISupportsString> msg(do_QueryInterface(aSubject));
      MOZ_ASSERT(msg);
      msg->GetData(errorMessage);
      if (errorMessage.IsEmpty())
        errorMessage.AssignLiteral(MOZ_UTF16("InternalError"));
    }

    nsString key(aData);
    nsAutoPtr<GetUserMediaTask> task;
    mActiveCallbacks.RemoveAndForget(key, task);
    if (task) {
      task->Denied(errorMessage);
    }
    return NS_OK;

  } else if (!strcmp(aTopic, "getUserMedia:revoke")) {
    nsresult rv;
    // may be windowid or screen:windowid
    nsDependentString data(aData);
    if (Substring(data, 0, strlen("screen:")).EqualsLiteral("screen:")) {
      uint64_t windowID = PromiseFlatString(Substring(data, strlen("screen:"))).ToInteger64(&rv);
      MOZ_ASSERT(NS_SUCCEEDED(rv));
      if (NS_SUCCEEDED(rv)) {
        LOG(("Revoking Screen/windowCapture access for window %llu", windowID));
        StopScreensharing(windowID);
      }
    } else {
      uint64_t windowID = nsString(aData).ToInteger64(&rv);
      MOZ_ASSERT(NS_SUCCEEDED(rv));
      if (NS_SUCCEEDED(rv)) {
        LOG(("Revoking MediaCapture access for window %llu", windowID));
        OnNavigation(windowID);
      }
    }
    return NS_OK;
  }
#ifdef MOZ_WIDGET_GONK
  else if (!strcmp(aTopic, "phone-state-changed")) {
    nsString state(aData);
    nsresult rv;
    uint32_t phoneState = state.ToInteger(&rv);

    if (NS_SUCCEEDED(rv) && phoneState == nsIAudioManager::PHONE_STATE_IN_CALL) {
      StopMediaStreams();
    }
    return NS_OK;
  }
#endif

  return NS_OK;
}

static PLDHashOperator
WindowsHashToArrayFunc (const uint64_t& aId,
                        StreamListeners* aData,
                        void *userArg)
{
  nsISupportsArray *array =
    static_cast<nsISupportsArray *>(userArg);
  nsPIDOMWindow *window = static_cast<nsPIDOMWindow*>
    (nsGlobalWindow::GetInnerWindowWithId(aId));

  MOZ_ASSERT(window);
  if (window) {
    // mActiveWindows contains both windows that have requested device
    // access and windows that are currently capturing media. We want
    // to return only the latter. See bug 975177.
    bool capturing = false;
    if (aData) {
      uint32_t length = aData->Length();
      for (uint32_t i = 0; i < length; ++i) {
        nsRefPtr<GetUserMediaCallbackMediaStreamListener> listener =
          aData->ElementAt(i);
        if (listener->CapturingVideo() || listener->CapturingAudio() ||
            listener->CapturingScreen() || listener->CapturingWindow() ||
            listener->CapturingApplication()) {
          capturing = true;
          break;
        }
      }
    }

    if (capturing)
      array->AppendElement(window);
  }
  return PL_DHASH_NEXT;
}


nsresult
MediaManager::GetActiveMediaCaptureWindows(nsISupportsArray **aArray)
{
  MOZ_ASSERT(aArray);
  nsISupportsArray *array;
  nsresult rv = NS_NewISupportsArray(&array); // AddRefs
  if (NS_FAILED(rv))
    return rv;

  mActiveWindows.EnumerateRead(WindowsHashToArrayFunc, array);

  *aArray = array;
  return NS_OK;
}

// XXX flags might be better...
struct CaptureWindowStateData {
  bool *mVideo;
  bool *mAudio;
  bool *mScreenShare;
  bool *mWindowShare;
  bool *mAppShare;
  bool *mBrowserShare;
};

static void
CaptureWindowStateCallback(MediaManager *aThis,
                           uint64_t aWindowID,
                           StreamListeners *aListeners,
                           void *aData)
{
  struct CaptureWindowStateData *data = (struct CaptureWindowStateData *) aData;

  if (aListeners) {
    auto length = aListeners->Length();
    for (size_t i = 0; i < length; ++i) {
      GetUserMediaCallbackMediaStreamListener *listener = aListeners->ElementAt(i);

      if (listener->CapturingVideo()) {
        *data->mVideo = true;
      }
      if (listener->CapturingAudio()) {
        *data->mAudio = true;
      }
      if (listener->CapturingScreen()) {
        *data->mScreenShare = true;
      }
      if (listener->CapturingWindow()) {
        *data->mWindowShare = true;
      }
      if (listener->CapturingApplication()) {
        *data->mAppShare = true;
      }
      if (listener->CapturingBrowser()) {
        *data->mBrowserShare = true;
      }
    }
  }
}


NS_IMETHODIMP
MediaManager::MediaCaptureWindowState(nsIDOMWindow* aWindow, bool* aVideo,
                                      bool* aAudio, bool *aScreenShare,
                                      bool* aWindowShare, bool *aAppShare,
                                      bool *aBrowserShare)
{
  NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
  struct CaptureWindowStateData data;
  data.mVideo = aVideo;
  data.mAudio = aAudio;
  data.mScreenShare = aScreenShare;
  data.mWindowShare = aWindowShare;
  data.mAppShare = aAppShare;
  data.mBrowserShare = aBrowserShare;

  *aVideo = false;
  *aAudio = false;
  *aScreenShare = false;
  *aWindowShare = false;
  *aAppShare = false;
  *aBrowserShare = false;

  nsCOMPtr<nsPIDOMWindow> piWin = do_QueryInterface(aWindow);
  if (piWin) {
    IterateWindowListeners(piWin, CaptureWindowStateCallback, &data);
  }
#ifdef DEBUG
  LOG(("%s: window %lld capturing %s %s %s %s %s %s", __FUNCTION__, piWin ? piWin->WindowID() : -1,
       *aVideo ? "video" : "", *aAudio ? "audio" : "",
       *aScreenShare ? "screenshare" : "",  *aWindowShare ? "windowshare" : "",
       *aAppShare ? "appshare" : "", *aBrowserShare ? "browsershare" : ""));
#endif
  return NS_OK;
}

NS_IMETHODIMP
MediaManager::SanitizeDeviceIds(int64_t aSinceWhen)
{
  NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
  LOG(("%s: sinceWhen = %llu", __FUNCTION__, aSinceWhen));

  media::SanitizeOriginKeys(aSinceWhen, false); // we fire and forget
  return NS_OK;
}

static void
StopScreensharingCallback(MediaManager *aThis,
                          uint64_t aWindowID,
                          StreamListeners *aListeners,
                          void *aData)
{
  if (aListeners) {
    auto length = aListeners->Length();
    for (size_t i = 0; i < length; ++i) {
      aListeners->ElementAt(i)->StopSharing();
    }
  }
}

void
MediaManager::StopScreensharing(uint64_t aWindowID)
{
  // We need to stop window/screensharing for all streams in all innerwindows that
  // correspond to that outerwindow.

  nsPIDOMWindow *window = static_cast<nsPIDOMWindow*>
      (nsGlobalWindow::GetInnerWindowWithId(aWindowID));
  if (!window) {
    return;
  }
  IterateWindowListeners(window, &StopScreensharingCallback, nullptr);
}

// lets us do all sorts of things to the listeners
void
MediaManager::IterateWindowListeners(nsPIDOMWindow *aWindow,
                                     WindowListenerCallback aCallback,
                                     void *aData)
{
  // Iterate the docshell tree to find all the child windows, and for each
  // invoke the callback
  nsCOMPtr<nsPIDOMWindow> piWin = do_QueryInterface(aWindow);
  if (piWin) {
    if (piWin->IsInnerWindow() || piWin->GetCurrentInnerWindow()) {
      uint64_t windowID;
      if (piWin->IsInnerWindow()) {
        windowID = piWin->WindowID();
      } else {
        windowID = piWin->GetCurrentInnerWindow()->WindowID();
      }
      StreamListeners* listeners = GetActiveWindows()->Get(windowID);
      // pass listeners so it can modify/delete the list
      (*aCallback)(this, windowID, listeners, aData);
    }

    // iterate any children of *this* window (iframes, etc)
    nsCOMPtr<nsIDocShell> docShell = piWin->GetDocShell();
    if (docShell) {
      int32_t i, count;
      docShell->GetChildCount(&count);
      for (i = 0; i < count; ++i) {
        nsCOMPtr<nsIDocShellTreeItem> item;
        docShell->GetChildAt(i, getter_AddRefs(item));
        nsCOMPtr<nsPIDOMWindow> win = item ? item->GetWindow() : nullptr;

        if (win) {
          IterateWindowListeners(win, aCallback, aData);
        }
      }
    }
  }
}


void
MediaManager::StopMediaStreams()
{
  nsCOMPtr<nsISupportsArray> array;
  GetActiveMediaCaptureWindows(getter_AddRefs(array));
  uint32_t len;
  array->Count(&len);
  for (uint32_t i = 0; i < len; i++) {
    nsCOMPtr<nsISupports> window;
    array->GetElementAt(i, getter_AddRefs(window));
    nsCOMPtr<nsPIDOMWindow> win(do_QueryInterface(window));
    if (win) {
      OnNavigation(win->WindowID());
    }
  }
}

bool
MediaManager::IsActivelyCapturingOrHasAPermission(uint64_t aWindowId)
{
  // Does page currently have a gUM stream active?

  nsCOMPtr<nsISupportsArray> array;
  GetActiveMediaCaptureWindows(getter_AddRefs(array));
  uint32_t len;
  array->Count(&len);
  for (uint32_t i = 0; i < len; i++) {
    nsCOMPtr<nsISupports> window;
    array->GetElementAt(i, getter_AddRefs(window));
    nsCOMPtr<nsPIDOMWindow> win(do_QueryInterface(window));
    if (win && win->WindowID() == aWindowId) {
      return true;
    }
  }

  // Or are persistent permissions (audio or video) granted?

  nsPIDOMWindow *window = static_cast<nsPIDOMWindow*>
      (nsGlobalWindow::GetInnerWindowWithId(aWindowId));
  if (NS_WARN_IF(!window)) {
    return false;
  }
  // Check if this site has persistent permissions.
  nsresult rv;
  nsCOMPtr<nsIPermissionManager> mgr =
    do_GetService(NS_PERMISSIONMANAGER_CONTRACTID, &rv);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return false; // no permission manager no permissions!
  }

  uint32_t audio = nsIPermissionManager::UNKNOWN_ACTION;
  uint32_t video = nsIPermissionManager::UNKNOWN_ACTION;
  {
    auto* principal = window->GetExtantDoc()->NodePrincipal();
    rv = mgr->TestExactPermissionFromPrincipal(principal, "microphone", &audio);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return false;
    }
    rv = mgr->TestExactPermissionFromPrincipal(principal, "camera", &video);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return false;
    }
  }
  return audio == nsIPermissionManager::ALLOW_ACTION ||
         video == nsIPermissionManager::ALLOW_ACTION;
}

void
GetUserMediaCallbackMediaStreamListener::AudioConfig(bool aEchoOn,
              uint32_t aEcho,
              bool aAgcOn, uint32_t aAGC,
              bool aNoiseOn, uint32_t aNoise,
              int32_t aPlayoutDelay)
{
  if (mAudioSource) {
#ifdef MOZ_WEBRTC
    MediaManager::PostTask(FROM_HERE,
      NewRunnableMethod(mAudioSource.get(), &MediaEngineSource::Config,
                        aEchoOn, aEcho, aAgcOn, aAGC, aNoiseOn,
                        aNoise, aPlayoutDelay));
#endif
  }
}

// Can be invoked from EITHER MainThread or MSG thread
void
GetUserMediaCallbackMediaStreamListener::Invalidate()
{
  // We can't take a chance on blocking here, so proxy this to another
  // thread.
  // Pass a ref to us (which is threadsafe) so it can query us for the
  // source stream info.
  MediaManager::PostTask(FROM_HERE,
    new MediaOperationTask(MEDIA_STOP,
                           this, nullptr, nullptr,
                           mAudioSource, mVideoSource,
                           mFinished, mWindowID, nullptr));
}

// Doesn't kill audio
// XXX refactor to combine with Invalidate()?
void
GetUserMediaCallbackMediaStreamListener::StopSharing()
{
  NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
  if (mVideoSource && !mStopped &&
      (mVideoSource->GetMediaSource() == dom::MediaSourceEnum::Screen ||
       mVideoSource->GetMediaSource() == dom::MediaSourceEnum::Application ||
       mVideoSource->GetMediaSource() == dom::MediaSourceEnum::Window)) {
    // Stop the whole stream if there's no audio; just the video track if we have both
    MediaManager::PostTask(FROM_HERE,
      new MediaOperationTask(mAudioSource ? MEDIA_STOP_TRACK : MEDIA_STOP,
                             this, nullptr, nullptr,
                             nullptr, mVideoSource,
                             mFinished, mWindowID, nullptr));
  } else if (mAudioSource &&
             mAudioSource->GetMediaSource() == dom::MediaSourceEnum::AudioCapture) {
    nsCOMPtr<nsPIDOMWindow> window = nsGlobalWindow::GetInnerWindowWithId(mWindowID);
    MOZ_ASSERT(window);
    window->SetAudioCapture(false);
    MediaStreamGraph* graph =
      MediaStreamGraph::GetInstance(MediaStreamGraph::AUDIO_THREAD_DRIVER,
                                    dom::AudioChannel::Normal);
    graph->UnregisterCaptureStreamForWindow(mWindowID);
    mStream->Destroy();
  }
}

// Stop backend for track

void
GetUserMediaCallbackMediaStreamListener::StopTrack(TrackID aID, bool aIsAudio)
{
  if (((aIsAudio && mAudioSource) ||
       (!aIsAudio && mVideoSource)) && !mStopped)
  {
    // XXX to support multiple tracks of a type in a stream, this should key off
    // the TrackID and not just the type
    MediaManager::PostTask(FROM_HERE,
      new MediaOperationTask(MEDIA_STOP_TRACK,
                             this, nullptr, nullptr,
                             aIsAudio  ? mAudioSource.get() : nullptr,
                             !aIsAudio ? mVideoSource.get() : nullptr,
                             mFinished, mWindowID, nullptr));
  } else {
    LOG(("gUM track %d ended, but we don't have type %s",
         aID, aIsAudio ? "audio" : "video"));
  }
}

// Called from the MediaStreamGraph thread
void
GetUserMediaCallbackMediaStreamListener::NotifyFinished(MediaStreamGraph* aGraph)
{
  mFinished = true;
  Invalidate(); // we know it's been activated
  NS_DispatchToMainThread(do_AddRef(new GetUserMediaListenerRemove(mWindowID, this)));
}

// Called from the MediaStreamGraph thread
void
GetUserMediaCallbackMediaStreamListener::NotifyDirectListeners(MediaStreamGraph* aGraph,
                                                               bool aHasListeners)
{
  MediaManager::PostTask(FROM_HERE,
    new MediaOperationTask(MEDIA_DIRECT_LISTENERS,
                           this, nullptr, nullptr,
                           mAudioSource, mVideoSource,
                           aHasListeners, mWindowID, nullptr));
}

// Called from the MediaStreamGraph thread
// this can be in response to our own RemoveListener() (via ::Remove()), or
// because the DOM GC'd the DOMLocalMediaStream/etc we're attached to.
void
GetUserMediaCallbackMediaStreamListener::NotifyRemoved(MediaStreamGraph* aGraph)
{
  {
    MutexAutoLock lock(mLock); // protect access to mRemoved
    MM_LOG(("Listener removed by DOM Destroy(), mFinished = %d", (int) mFinished));
    mRemoved = true;
  }
  if (!mFinished) {
    NotifyFinished(aGraph);
  }
}

NS_IMETHODIMP
GetUserMediaNotificationEvent::Run()
{
  NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
  // Make sure mStream is cleared and our reference to the DOMMediaStream
  // is dropped on the main thread, no matter what happens in this method.
  // Otherwise this object might be destroyed off the main thread,
  // releasing DOMMediaStream off the main thread, which is not allowed.
  nsRefPtr<DOMMediaStream> stream = mStream.forget();

  nsString msg;
  switch (mStatus) {
  case STARTING:
    msg = NS_LITERAL_STRING("starting");
    stream->OnTracksAvailable(mOnTracksAvailableCallback.forget());
    break;
  case STOPPING:
    msg = NS_LITERAL_STRING("shutdown");
    if (mListener) {
      mListener->SetStopped();
    }
    break;
  case STOPPED_TRACK:
    msg = NS_LITERAL_STRING("shutdown");
    break;
  }

  nsCOMPtr<nsPIDOMWindow> window = nsGlobalWindow::GetInnerWindowWithId(mWindowID);
  NS_ENSURE_TRUE(window, NS_ERROR_FAILURE);

  return MediaManager::NotifyRecordingStatusChange(window, msg, mIsAudio, mIsVideo);
}

} // namespace mozilla