Bug 1180940 - Changed return type of AudioDestinationNode::CreateAudioChannelAgent method to return errors, if any methods that it calls fail. Added code to handle the return value in AudioContext::Init(), and its callers. r=baku

dom/audiochannel/AudioChannelAgent.cpp

@@ -104,7 +104,7 @@ AudioChannelAgent::InitInternal(nsIDOMWindow* aWindow, int32_t aChannelType,
   }
 
   if (NS_WARN_IF(!aWindow)) {
-    return NS_ERROR_FAILURE;
+    return NS_OK;
   }
 
   nsCOMPtr<nsPIDOMWindow> pInnerWindow = do_QueryInterface(aWindow);
@@ -113,6 +113,10 @@ AudioChannelAgent::InitInternal(nsIDOMWindow* aWindow, int32_t aChannelType,
 
   nsCOMPtr<nsIDOMWindow> topWindow;
   aWindow->GetScriptableTop(getter_AddRefs(topWindow));
+  if (NS_WARN_IF(!topWindow)) {
+    return NS_OK;
+  }
+
   mWindow = do_QueryInterface(topWindow);
   if (mWindow) {
     mWindow = mWindow->GetOuterWindow();

dom/media/webaudio/AudioContext.cpp

@@ -117,14 +117,21 @@ AudioContext::AudioContext(nsPIDOMWindow* aWindow,
   }
 }
 
-void
+nsresult
 AudioContext::Init()
 {
   // We skip calling SetIsOnlyNodeForContext and the creation of the
   // audioChannelAgent during mDestination's constructor, because we can only
   // call them after mDestination has been set up.
-  mDestination->CreateAudioChannelAgent();
-  mDestination->SetIsOnlyNodeForContext(true);
+  if (!mIsOffline) {
+    nsresult rv = mDestination->CreateAudioChannelAgent();
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+    mDestination->SetIsOnlyNodeForContext(true);
+  }
+
+  return NS_OK;
 }
 
 AudioContext::~AudioContext()
@@ -160,7 +167,10 @@ AudioContext::Constructor(const GlobalObject& aGlobal,
   nsRefPtr<AudioContext> object =
     new AudioContext(window, false,
                      AudioChannelService::GetDefaultAudioChannel());
-  object->Init();
+  aRv = object->Init();
+  if (NS_WARN_IF(aRv.Failed())) {
+     return nullptr;
+  }
 
   RegisterWeakMemoryReporter(object);
 
@@ -179,7 +189,10 @@ AudioContext::Constructor(const GlobalObject& aGlobal,
   }
 
   nsRefPtr<AudioContext> object = new AudioContext(window, false, aChannel);
-  object->Init();
+  aRv = object->Init();
+  if (NS_WARN_IF(aRv.Failed())) {
+     return nullptr;
+  }
 
   RegisterWeakMemoryReporter(object);
 

dom/media/webaudio/AudioContext.h

@@ -124,7 +124,7 @@ class AudioContext final : public DOMEventTargetHelper,
                float aSampleRate = 0.0f);
   ~AudioContext();
 
-  void Init();
+  nsresult Init();
 
 public:
   typedef uint64_t AudioContextId;

dom/media/webaudio/AudioDestinationNode.cpp

@@ -629,23 +629,33 @@ AudioDestinationNode::CheckAudioChannelPermissions(AudioChannel aValue)
   return perm == nsIPermissionManager::ALLOW_ACTION;
 }
 
-void
+nsresult
 AudioDestinationNode::CreateAudioChannelAgent()
 {
   if (mIsOffline) {
-    return;
+    return NS_OK;
   }
 
+  nsresult rv = NS_OK;
   if (mAudioChannelAgent) {
-    mAudioChannelAgent->NotifyStoppedPlaying(nsIAudioChannelAgent::AUDIO_AGENT_NOTIFY);
+    rv = mAudioChannelAgent->NotifyStoppedPlaying(nsIAudioChannelAgent::AUDIO_AGENT_NOTIFY);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
   }
 
   mAudioChannelAgent = new AudioChannelAgent();
-  mAudioChannelAgent->InitWithWeakCallback(GetOwner(),
+  rv = mAudioChannelAgent->InitWithWeakCallback(GetOwner(),
                                            static_cast<int32_t>(mAudioChannel),
                                            this);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = WindowAudioCaptureChanged();
+  NS_WARN_IF(NS_FAILED(rv));
+  return rv;
 
-  WindowAudioCaptureChanged();
 }
 
 void

dom/media/webaudio/AudioDestinationNode.h

@@ -73,7 +73,7 @@ public:
   // When aIsOnlyNode is true, this is the only node for the AudioContext.
   void SetIsOnlyNodeForContext(bool aIsOnlyNode);
 
-  void CreateAudioChannelAgent();
+  nsresult CreateAudioChannelAgent();
   void DestroyAudioChannelAgent();
 
   virtual const char* NodeType() const override