diff --git a/content/html/content/public/HTMLMediaElement.h b/content/html/content/public/HTMLMediaElement.h
index 7bcb547493f..7791da16210 100644
--- a/content/html/content/public/HTMLMediaElement.h
+++ b/content/html/content/public/HTMLMediaElement.h
@@ -39,6 +39,7 @@ class VideoFrameContainer;
 namespace dom {
 class TextTrack;
 class TimeRanges;
+class WakeLock;
 }
 }
 
@@ -588,7 +589,7 @@ protected:
    */
   virtual void WakeLockCreate();
   virtual void WakeLockRelease();
-  nsCOMPtr<nsIDOMMozWakeLock> mWakeLock;
+  nsRefPtr<WakeLock> mWakeLock;
 
   /**
    * Logs a warning message to the web console to report various failures.
diff --git a/content/html/content/public/HTMLVideoElement.h b/content/html/content/public/HTMLVideoElement.h
index 283e08e6f0a..133b7c1297f 100644
--- a/content/html/content/public/HTMLVideoElement.h
+++ b/content/html/content/public/HTMLVideoElement.h
@@ -14,6 +14,7 @@
 namespace mozilla {
 namespace dom {
 
+class WakeLock;
 class VideoPlaybackQuality;
 
 class HTMLVideoElement MOZ_FINAL : public HTMLMediaElement,
@@ -115,7 +116,7 @@ protected:
   virtual void WakeLockRelease();
   void WakeLockUpdate();
 
-  nsCOMPtr<nsIDOMMozWakeLock> mScreenWakeLock;
+  nsRefPtr<WakeLock> mScreenWakeLock;
 
 private:
   static void MapAttributesIntoRule(const nsMappedAttributes* aAttributes,
diff --git a/content/html/content/src/HTMLMediaElement.cpp b/content/html/content/src/HTMLMediaElement.cpp
index 95fe7f24cfd..ff1dcff3aa2 100644
--- a/content/html/content/src/HTMLMediaElement.cpp
+++ b/content/html/content/src/HTMLMediaElement.cpp
@@ -75,10 +75,10 @@
 
 #include "nsCSSParser.h"
 #include "nsIMediaList.h"
-#include "nsIDOMWakeLock.h"
+#include "mozilla/dom/power/PowerManagerService.h"
+#include "mozilla/dom/WakeLock.h"
 
 #include "ImageContainer.h"
-#include "nsIPowerManagerService.h"
 #include "nsRange.h"
 #include <algorithm>
 
@@ -2245,13 +2245,14 @@ void
 HTMLMediaElement::WakeLockCreate()
 {
   if (!mWakeLock) {
-    nsCOMPtr<nsIPowerManagerService> pmService =
-      do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+    nsRefPtr<power::PowerManagerService> pmService =
+      power::PowerManagerService::GetInstance();
     NS_ENSURE_TRUE_VOID(pmService);
 
-    pmService->NewWakeLock(NS_LITERAL_STRING("cpu"),
-                           OwnerDoc()->GetWindow(),
-                           getter_AddRefs(mWakeLock));
+    ErrorResult rv;
+    mWakeLock = pmService->NewWakeLock(NS_LITERAL_STRING("cpu"),
+                                       OwnerDoc()->GetInnerWindow(),
+                                       rv);
   }
 }
 
@@ -2259,7 +2260,9 @@ void
 HTMLMediaElement::WakeLockRelease()
 {
   if (mWakeLock) {
-    mWakeLock->Unlock();
+    ErrorResult rv;
+    mWakeLock->Unlock(rv);
+    NS_WARN_IF_FALSE(!rv.Failed(), "Failed to unlock the wakelock.");
     mWakeLock = nullptr;
   }
 }
diff --git a/content/html/content/src/HTMLVideoElement.cpp b/content/html/content/src/HTMLVideoElement.cpp
index 1bc49191876..0d096acc8f9 100644
--- a/content/html/content/src/HTMLVideoElement.cpp
+++ b/content/html/content/src/HTMLVideoElement.cpp
@@ -27,11 +27,11 @@
 
 #include "nsEventDispatcher.h"
 #include "nsIDOMProgressEvent.h"
-#include "nsIPowerManagerService.h"
 #include "MediaError.h"
 #include "MediaDecoder.h"
 #include "mozilla/Preferences.h"
-#include "nsIDOMWakeLock.h"
+#include "mozilla/dom/WakeLock.h"
+#include "mozilla/dom/power/PowerManagerService.h"
 #include "nsPerformance.h"
 #include "mozilla/dom/VideoPlaybackQuality.h"
 
@@ -302,19 +302,22 @@ HTMLVideoElement::WakeLockUpdate()
   bool hidden = OwnerDoc()->Hidden();
 
   if (mScreenWakeLock && (mPaused || hidden)) {
-    mScreenWakeLock->Unlock();
+    ErrorResult rv;
+    mScreenWakeLock->Unlock(rv);
+    NS_WARN_IF_FALSE(!rv.Failed(), "Failed to unlock the wakelock.");
     mScreenWakeLock = nullptr;
     return;
   }
 
   if (!mScreenWakeLock && !mPaused && !hidden) {
-    nsCOMPtr<nsIPowerManagerService> pmService =
-      do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+    nsRefPtr<power::PowerManagerService> pmService =
+      power::PowerManagerService::GetInstance();
     NS_ENSURE_TRUE_VOID(pmService);
 
-    pmService->NewWakeLock(NS_LITERAL_STRING("screen"),
-                           OwnerDoc()->GetWindow(),
-                           getter_AddRefs(mScreenWakeLock));
+    ErrorResult rv;
+    mScreenWakeLock = pmService->NewWakeLock(NS_LITERAL_STRING("screen"),
+                                             OwnerDoc()->GetInnerWindow(),
+                                             rv);
   }
 }
 
diff --git a/dom/base/Navigator.cpp b/dom/base/Navigator.cpp
index fcacef59630..2c28b10cc5d 100644
--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -26,8 +26,8 @@
 #include "mozilla/Telemetry.h"
 #include "BatteryManager.h"
 #include "mozilla/dom/PowerManager.h"
-#include "nsIDOMWakeLock.h"
-#include "nsIPowerManagerService.h"
+#include "mozilla/dom/WakeLock.h"
+#include "mozilla/dom/power/PowerManagerService.h"
 #include "mozilla/dom/MobileMessageManager.h"
 #include "mozilla/dom/Telephony.h"
 #include "mozilla/Hal.h"
@@ -1131,7 +1131,7 @@ Navigator::GetMozPower(ErrorResult& aRv)
   return mPowerManager;
 }
 
-already_AddRefed<nsIDOMMozWakeLock>
+already_AddRefed<WakeLock>
 Navigator::RequestWakeLock(const nsAString &aTopic, ErrorResult& aRv)
 {
   if (!mWindow) {
@@ -1139,15 +1139,14 @@ Navigator::RequestWakeLock(const nsAString &aTopic, ErrorResult& aRv)
     return nullptr;
   }
 
-  nsCOMPtr<nsIPowerManagerService> pmService =
-    do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+  nsRefPtr<power::PowerManagerService> pmService =
+    power::PowerManagerService::GetInstance();
   // Maybe it went away for some reason... Or maybe we're just called
   // from our XPCOM method.
   NS_ENSURE_TRUE(pmService, nullptr);
 
-  nsCOMPtr<nsIDOMMozWakeLock> wakelock;
-  aRv = pmService->NewWakeLock(aTopic, mWindow, getter_AddRefs(wakelock));
-  return wakelock.forget();
+  ErrorResult rv;
+  return pmService->NewWakeLock(aTopic, mWindow, rv);
 }
 
 nsIDOMMozMobileMessageManager*
diff --git a/dom/base/Navigator.h b/dom/base/Navigator.h
index 282b3c51bd6..9a05a7cf29a 100644
--- a/dom/base/Navigator.h
+++ b/dom/base/Navigator.h
@@ -31,6 +31,7 @@ class Geolocation;
 class systemMessageCallback;
 class MediaStreamConstraints;
 class MediaStreamConstraintsInternal;
+class WakeLock;
 }
 }
 
@@ -182,8 +183,8 @@ public:
   }
   void AddIdleObserver(MozIdleObserver& aObserver, ErrorResult& aRv);
   void RemoveIdleObserver(MozIdleObserver& aObserver, ErrorResult& aRv);
-  already_AddRefed<nsIDOMMozWakeLock> RequestWakeLock(const nsAString &aTopic,
-                                                      ErrorResult& aRv);
+  already_AddRefed<WakeLock> RequestWakeLock(const nsAString &aTopic,
+                                             ErrorResult& aRv);
   nsDOMDeviceStorage* GetDeviceStorage(const nsAString& aType,
                                        ErrorResult& aRv);
   void GetDeviceStorages(const nsAString& aType,
diff --git a/dom/base/nsDOMClassInfo.cpp b/dom/base/nsDOMClassInfo.cpp
index a43053894e2..fe4e30f75a5 100644
--- a/dom/base/nsDOMClassInfo.cpp
+++ b/dom/base/nsDOMClassInfo.cpp
@@ -148,7 +148,6 @@
 #include "nsWrapperCacheInlines.h"
 #include "mozilla/dom/HTMLCollectionBinding.h"
 
-#include "nsIDOMWakeLock.h"
 #include "nsIDOMMobileMessageManager.h"
 #include "nsIDOMMozSmsMessage.h"
 #include "nsIDOMMozMmsMessage.h"
@@ -436,9 +435,6 @@ static nsDOMClassInfoData sClassInfoData[] = {
                            DEFAULT_SCRIPTABLE_FLAGS |
                            WINDOW_SCRIPTABLE_FLAGS)
 
-  NS_DEFINE_CLASSINFO_DATA(MozWakeLock, nsDOMGenericSH,
-                           DOM_DEFAULT_SCRIPTABLE_FLAGS)
-
   NS_DEFINE_CLASSINFO_DATA(MozMobileMessageManager, nsDOMGenericSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS)
 
@@ -1127,10 +1123,6 @@ nsDOMClassInfo::Init()
 #endif
   DOM_CLASSINFO_MAP_END
 
-  DOM_CLASSINFO_MAP_BEGIN(MozWakeLock, nsIDOMMozWakeLock)
-     DOM_CLASSINFO_MAP_ENTRY(nsIDOMMozWakeLock)
-  DOM_CLASSINFO_MAP_END
-
   DOM_CLASSINFO_MAP_BEGIN(MozMobileMessageManager, nsIDOMMozMobileMessageManager)
      DOM_CLASSINFO_MAP_ENTRY(nsIDOMMozMobileMessageManager)
   DOM_CLASSINFO_MAP_END
diff --git a/dom/base/nsDOMClassInfoClasses.h b/dom/base/nsDOMClassInfoClasses.h
index c88a8252ba1..b9e603329d5 100644
--- a/dom/base/nsDOMClassInfoClasses.h
+++ b/dom/base/nsDOMClassInfoClasses.h
@@ -77,8 +77,6 @@ DOMCI_CLASS(File)
 // DOM modal content window class, almost identical to Window
 DOMCI_CLASS(ModalContentWindow)
 
-DOMCI_CLASS(MozWakeLock)
-
 DOMCI_CLASS(MozMobileMessageManager)
 DOMCI_CLASS(MozSmsMessage)
 DOMCI_CLASS(MozMmsMessage)
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 9145301449d..891504f4dc2 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -22,13 +22,13 @@
 #include "nsDOMOfflineResourceList.h"
 #include "nsError.h"
 #include "nsIIdleService.h"
-#include "nsIPowerManagerService.h"
 #include "nsISizeOfEventTarget.h"
 #include "nsDOMJSUtils.h"
 #include "nsArrayUtils.h"
 #include "nsIDOMWindowCollection.h"
 #include "nsDOMWindowList.h"
-#include "nsIDOMWakeLock.h"
+#include "mozilla/dom/WakeLock.h"
+#include "mozilla/dom/power/PowerManagerService.h"
 #include "nsIDocShellTreeOwner.h"
 #include "nsIPermissionManager.h"
 #include "nsIScriptContext.h"
@@ -5698,13 +5698,21 @@ nsGlobalWindow::SetFullScreenInternal(bool aFullScreen, bool aRequireTrust)
   }
 
   if (!mWakeLock && mFullScreen) {
-    nsCOMPtr<nsIPowerManagerService> pmService =
-      do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+    nsRefPtr<power::PowerManagerService> pmService =
+      power::PowerManagerService::GetInstance();
     NS_ENSURE_TRUE(pmService, NS_OK);
 
-    pmService->NewWakeLock(NS_LITERAL_STRING("DOM_Fullscreen"), this, getter_AddRefs(mWakeLock));
+    ErrorResult rv;
+    mWakeLock = pmService->NewWakeLock(NS_LITERAL_STRING("DOM_Fullscreen"),
+                                       this, rv);
+    if (rv.Failed()) {
+      return rv.ErrorCode();
+    }
+
   } else if (mWakeLock && !mFullScreen) {
-    mWakeLock->Unlock();
+    ErrorResult rv;
+    mWakeLock->Unlock(rv);
+    NS_WARN_IF_FALSE(!rv.Failed(), "Failed to unlock the wakelock.");
     mWakeLock = nullptr;
   }
 
diff --git a/dom/base/nsGlobalWindow.h b/dom/base/nsGlobalWindow.h
index c66bc75a596..cb12ec72f77 100644
--- a/dom/base/nsGlobalWindow.h
+++ b/dom/base/nsGlobalWindow.h
@@ -82,7 +82,6 @@ class nsICSSDeclaration;
 class nsIDocShellTreeOwner;
 class nsIDOMCrypto;
 class nsIDOMOfflineResourceList;
-class nsIDOMMozWakeLock;
 class nsIScrollableFrame;
 class nsIControllers;
 class nsIScriptContext;
@@ -112,6 +111,7 @@ class Gamepad;
 class MediaQueryList;
 class Navigator;
 class SpeechSynthesis;
+class WakeLock;
 namespace indexedDB {
 class IDBFactory;
 } // namespace indexedDB
@@ -972,7 +972,7 @@ protected:
 
   nsCOMPtr <nsIIdleService> mIdleService;
 
-  nsCOMPtr <nsIDOMMozWakeLock> mWakeLock;
+  nsRefPtr<mozilla::dom::WakeLock> mWakeLock;
 
   static bool sIdleObserversAPIFuzzTimeDisabled;
 
diff --git a/dom/bindings/Bindings.conf b/dom/bindings/Bindings.conf
index cb10ebe1f4f..9ba517bbe7f 100644
--- a/dom/bindings/Bindings.conf
+++ b/dom/bindings/Bindings.conf
@@ -822,6 +822,10 @@ DOMInterfaces = {
     'nativeType': 'mozilla::dom::PowerManager',
 },
 
+'MozWakeLock': {
+    'nativeType': 'mozilla::dom::WakeLock',
+},
+
 'MozTimeManager': {
     'nativeType': 'mozilla::dom::time::TimeManager',
 },
@@ -1896,7 +1900,6 @@ addExternalIface('MozTreeBoxObject', nativeType='nsITreeBoxObject',
 addExternalIface('MozTreeColumn', nativeType='nsITreeColumn',
                  headerFile='nsITreeColumns.h')
 addExternalIface('MozVoicemailStatus')
-addExternalIface('MozWakeLock', headerFile='nsIDOMWakeLock.h')
 addExternalIface('MozWakeLockListener', headerFile='nsIDOMWakeLockListener.h')
 addExternalIface('MozXULTemplateBuilder', nativeType='nsIXULTemplateBuilder')
 addExternalIface('nsIControllers', nativeType='nsIControllers')
diff --git a/dom/interfaces/base/domstubs.idl b/dom/interfaces/base/domstubs.idl
index db6156f1eaf..0f93e0e3ccd 100644
--- a/dom/interfaces/base/domstubs.idl
+++ b/dom/interfaces/base/domstubs.idl
@@ -83,6 +83,3 @@ interface nsIDOMPkcs11;
 // Used font face (for inspector)
 interface nsIDOMFontFace;
 interface nsIDOMFontFaceList;
-
-// Power
-interface nsIDOMMozWakeLock;
diff --git a/dom/ipc/ContentParent.cpp b/dom/ipc/ContentParent.cpp
index 855bfbf8781..5cbbf75a23c 100644
--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -64,7 +64,7 @@
 #include "nsIAppsService.h"
 #include "nsIClipboard.h"
 #include "nsIDOMGeoGeolocation.h"
-#include "nsIDOMWakeLock.h"
+#include "mozilla/dom/WakeLock.h"
 #include "nsIDOMWindow.h"
 #include "nsIExternalProtocolService.h"
 #include "nsIFilePicker.h"
@@ -713,7 +713,7 @@ public:
         listener->ShutDown();
     }
 
-    void Init(nsIDOMMozWakeLock* aWakeLock)
+    void Init(WakeLock* aWakeLock)
     {
         MOZ_ASSERT(!mWakeLock);
         MOZ_ASSERT(!mTimer);
@@ -751,7 +751,8 @@ private:
     {
         nsRefPtr<SystemMessageHandledListener> kungFuDeathGrip = this;
 
-        mWakeLock->Unlock();
+        ErrorResult rv;
+        mWakeLock->Unlock(rv);
 
         if (mTimer) {
             mTimer->Cancel();
@@ -759,7 +760,7 @@ private:
         }
     }
 
-    nsCOMPtr<nsIDOMMozWakeLock> mWakeLock;
+    nsRefPtr<WakeLock> mWakeLock;
     nsCOMPtr<nsITimer> mTimer;
 };
 
@@ -786,7 +787,7 @@ ContentParent::MaybeTakeCPUWakeLock(Element* aFrameElement)
     }
 
     nsRefPtr<PowerManagerService> pms = PowerManagerService::GetInstance();
-    nsCOMPtr<nsIDOMMozWakeLock> lock =
+    nsRefPtr<WakeLock> lock =
         pms->NewWakeLockOnBehalfOfProcess(NS_LITERAL_STRING("cpu"), this);
 
     // This object's Init() function keeps it alive.
diff --git a/dom/power/PowerManagerService.cpp b/dom/power/PowerManagerService.cpp
index 84eb5125512..c506c0c69c2 100644
--- a/dom/power/PowerManagerService.cpp
+++ b/dom/power/PowerManagerService.cpp
@@ -205,22 +205,37 @@ PowerManagerService::GetWakeLockState(const nsAString &aTopic, nsAString &aState
   return NS_OK;
 }
 
+already_AddRefed<WakeLock>
+PowerManagerService::NewWakeLock(const nsAString& aTopic,
+                                 nsIDOMWindow* aWindow,
+                                 mozilla::ErrorResult& aRv)
+{
+  nsRefPtr<WakeLock> wakelock = new WakeLock();
+  aRv = wakelock->Init(aTopic, aWindow);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  return wakelock.forget();
+}
+
 NS_IMETHODIMP
 PowerManagerService::NewWakeLock(const nsAString &aTopic,
                                  nsIDOMWindow *aWindow,
-                                 nsIDOMMozWakeLock **aWakeLock)
+                                 nsISupports **aWakeLock)
 {
-  nsRefPtr<WakeLock> wakelock = new WakeLock();
-  nsresult rv = wakelock->Init(aTopic, aWindow);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsCOMPtr<nsIDOMMozWakeLock> wl(wakelock);
-  wl.forget(aWakeLock);
+  mozilla::ErrorResult rv;
+  nsRefPtr<WakeLock> wakelock = NewWakeLock(aTopic, aWindow, rv);
+  if (rv.Failed()) {
+    return rv.ErrorCode();
+  }
 
+  nsCOMPtr<nsIDOMEventListener> eventListener = wakelock.get();
+  eventListener.forget(aWakeLock);
   return NS_OK;
 }
 
-already_AddRefed<nsIDOMMozWakeLock>
+already_AddRefed<WakeLock>
 PowerManagerService::NewWakeLockOnBehalfOfProcess(const nsAString& aTopic,
                                                   ContentParent* aContentParent)
 {
diff --git a/dom/power/PowerManagerService.h b/dom/power/PowerManagerService.h
index 7eae5f9e859..51a0660bb72 100644
--- a/dom/power/PowerManagerService.h
+++ b/dom/power/PowerManagerService.h
@@ -13,6 +13,7 @@
 #include "mozilla/Observer.h"
 #include "Types.h"
 #include "mozilla/StaticPtr.h"
+#include "mozilla/dom/WakeLock.h"
 
 namespace mozilla {
 namespace dom {
@@ -48,10 +49,14 @@ public:
    *  - The /given/ process shows up in WakeLockInfo::lockingProcesses.
    *
    */
-  already_AddRefed<nsIDOMMozWakeLock>
+  already_AddRefed<WakeLock>
   NewWakeLockOnBehalfOfProcess(const nsAString& aTopic,
                                ContentParent* aContentParent);
 
+  already_AddRefed<WakeLock>
+  NewWakeLock(const nsAString& aTopic, nsIDOMWindow* aWindow,
+              mozilla::ErrorResult& aRv);
+
 private:
 
   ~PowerManagerService();
diff --git a/dom/power/WakeLock.cpp b/dom/power/WakeLock.cpp
index aa5442ef31c..b923aee808d 100644
--- a/dom/power/WakeLock.cpp
+++ b/dom/power/WakeLock.cpp
@@ -5,9 +5,9 @@
 
 #include "WakeLock.h"
 #include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/MozWakeLockBinding.h"
 #include "mozilla/Hal.h"
 #include "mozilla/HalWakeLock.h"
-#include "nsDOMClassInfoID.h"
 #include "nsDOMEvent.h"
 #include "nsError.h"
 #include "nsIDocument.h"
@@ -16,31 +16,29 @@
 #include "nsPIDOMWindow.h"
 #include "nsIPropertyBag2.h"
 
-DOMCI_DATA(MozWakeLock, mozilla::dom::power::WakeLock)
-
 using namespace mozilla::hal;
 
 namespace mozilla {
 namespace dom {
-namespace power {
 
-NS_INTERFACE_MAP_BEGIN(WakeLock)
-  NS_INTERFACE_MAP_ENTRY(nsIDOMMozWakeLock)
-  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMMozWakeLock)
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(WakeLock)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(WakeLock)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener)
   NS_INTERFACE_MAP_ENTRY(nsIObserver)
   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
-  NS_DOM_INTERFACE_MAP_ENTRY_CLASSINFO(MozWakeLock)
 NS_INTERFACE_MAP_END
 
-NS_IMPL_ADDREF(WakeLock)
-NS_IMPL_RELEASE(WakeLock)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(WakeLock)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(WakeLock)
 
 WakeLock::WakeLock()
   : mLocked(false)
   , mHidden(true)
   , mContentParentID(CONTENT_PROCESS_ID_UNKNOWN)
 {
+  SetIsDOMBinding();
 }
 
 WakeLock::~WakeLock()
@@ -49,6 +47,12 @@ WakeLock::~WakeLock()
   DetachEventListener();
 }
 
+JSObject*
+WakeLock::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
+{
+  return MozWakeLockBinding::Wrap(aCx, aScope, this);
+}
+
 nsresult
 WakeLock::Init(const nsAString &aTopic, nsIDOMWindow *aWindow)
 {
@@ -212,27 +216,25 @@ WakeLock::DetachEventListener()
   }
 }
 
-NS_IMETHODIMP
-WakeLock::Unlock()
+void
+WakeLock::Unlock(ErrorResult& aRv)
 {
   /*
    * We throw NS_ERROR_DOM_INVALID_STATE_ERR on double unlock.
    */
   if (!mLocked) {
-    return NS_ERROR_DOM_INVALID_STATE_ERR;
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
   }
 
   DoUnlock();
   DetachEventListener();
-
-  return NS_OK;
 }
 
-NS_IMETHODIMP
+void
 WakeLock::GetTopic(nsAString &aTopic)
 {
   aTopic.Assign(mTopic);
-  return NS_OK;
 }
 
 NS_IMETHODIMP
@@ -272,6 +274,12 @@ WakeLock::HandleEvent(nsIDOMEvent *aEvent)
   return NS_OK;
 }
 
-} // power
+nsISupports*
+WakeLock::GetParentObject() const
+{
+  nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(mWindow);
+  return window;
+}
+
 } // dom
 } // mozilla
diff --git a/dom/power/WakeLock.h b/dom/power/WakeLock.h
index 410790c6cf4..aa5666b2755 100644
--- a/dom/power/WakeLock.h
+++ b/dom/power/WakeLock.h
@@ -7,11 +7,12 @@
 #define mozilla_dom_power_WakeLock_h
 
 #include "nsCOMPtr.h"
-#include "nsIDOMWakeLock.h"
 #include "nsIDOMEventListener.h"
 #include "nsIObserver.h"
 #include "nsString.h"
 #include "nsWeakReference.h"
+#include "nsWrapperCache.h"
+#include "mozilla/ErrorResult.h"
 
 class nsIDOMWindow;
 
@@ -20,20 +21,19 @@ namespace dom {
 
 class ContentParent;
 
-namespace power {
-
-class WakeLock
-  : public nsIDOMMozWakeLock
-  , public nsIDOMEventListener
+class WakeLock MOZ_FINAL
+  : public nsIDOMEventListener
+  , public nsWrapperCache
   , public nsIObserver
   , public nsSupportsWeakReference
 {
 public:
-  NS_DECL_ISUPPORTS
-  NS_DECL_NSIDOMMOZWAKELOCK
   NS_DECL_NSIDOMEVENTLISTENER
   NS_DECL_NSIOBSERVER
 
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(WakeLock, nsIDOMEventListener)
+
   // Note: WakeLock lives for the lifetime of the document in order to avoid
   // exposing GC behavior to pages. This means that
   // |var foo = navigator.requestWakeLock('cpu'); foo = null;|
@@ -52,6 +52,17 @@ public:
   // always considered visible.
   nsresult Init(const nsAString &aTopic, ContentParent* aContentParent);
 
+  // WebIDL methods
+
+  nsISupports* GetParentObject() const;
+
+  virtual JSObject*
+  WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
+
+  void GetTopic(nsAString& aTopic);
+
+  void Unlock(ErrorResult& aRv);
+
 private:
   void     DoUnlock();
   void     DoLock();
@@ -71,7 +82,6 @@ private:
   nsWeakPtr mWindow;
 };
 
-} // namespace power
 } // namespace dom
 } // namespace mozilla
 
diff --git a/dom/power/moz.build b/dom/power/moz.build
index 7e4b41ae69b..0f17275d7cd 100644
--- a/dom/power/moz.build
+++ b/dom/power/moz.build
@@ -8,7 +8,6 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
     TEST_DIRS += ['test']
 
 XPIDL_SOURCES += [
-    'nsIDOMWakeLock.idl',
     'nsIDOMWakeLockListener.idl',
     'nsIPowerManagerService.idl',
 ]
@@ -17,6 +16,7 @@ XPIDL_MODULE = 'dom_power'
 
 EXPORTS.mozilla.dom += [
     'PowerManager.h',
+    'WakeLock.h',
 ]
 
 EXPORTS.mozilla.dom.power += [
diff --git a/dom/power/nsIPowerManagerService.idl b/dom/power/nsIPowerManagerService.idl
index f06077f5621..9ff4da4a8c3 100644
--- a/dom/power/nsIPowerManagerService.idl
+++ b/dom/power/nsIPowerManagerService.idl
@@ -10,7 +10,6 @@
 #define POWERMANAGERSERVICE_CONTRACTID "@mozilla.org/power/powermanagerservice;1"
 %}
 
-interface nsIDOMMozWakeLock;
 interface nsIDOMMozWakeLockListener;
 interface nsIDOMWindow;
 
@@ -40,9 +39,9 @@ interface nsIPowerManagerService : nsISupports
   DOMString         getWakeLockState(in DOMString aTopic);
 
   /**
-   * Return a wake lock object of aTopic associated with aWindow.
+   * Return a wake lock (MozWakeLock) object of aTopic associated with aWindow.
    * A wake lock without associated window, e.g. used in chrome, is
    * always considered invisible.
    */
-  nsIDOMMozWakeLock newWakeLock(in DOMString aTopic, [optional] in nsIDOMWindow aWindow);
+  nsISupports newWakeLock(in DOMString aTopic, [optional] in nsIDOMWindow aWindow);
 };
diff --git a/dom/system/gonk/nsIVolume.idl b/dom/system/gonk/nsIVolume.idl
index a1abc686675..6cb47d0703f 100644
--- a/dom/system/gonk/nsIVolume.idl
+++ b/dom/system/gonk/nsIVolume.idl
@@ -39,7 +39,7 @@ interface nsIVolume : nsISupports
   readonly attribute long mountGeneration;
 
   // While a volume is mounted, it can be locked, preventing it from being
-  // shared with the PC. To lock a volume, acquire an nsIDOMMozWakeLock
+  // shared with the PC. To lock a volume, acquire an MozWakeLock
   // using the name of this attribute. Note that mountLockName changes
   // every time the mountGeneration changes, so you'll need to reacquire
   // the wakelock every time the volume becomes mounted.
diff --git a/dom/system/gonk/nsVolumeMountLock.cpp b/dom/system/gonk/nsVolumeMountLock.cpp
index a50d567ca83..f3917a7ab4d 100644
--- a/dom/system/gonk/nsVolumeMountLock.cpp
+++ b/dom/system/gonk/nsVolumeMountLock.cpp
@@ -17,6 +17,7 @@
 #define VOLUME_MANAGER_LOG_TAG  "nsVolumeMountLock"
 #include "VolumeManagerLog.h"
 #include "nsServiceManagerUtils.h"
+#include "mozilla/dom/power/PowerManagerService.h"
 
 using namespace mozilla::dom;
 using namespace mozilla::services;
@@ -141,14 +142,18 @@ NS_IMETHODIMP nsVolumeMountLock::Observe(nsISupports* aSubject, const char* aTop
   mWakeLock = nullptr;
   mVolumeGeneration = mountGeneration;
 
-  nsCOMPtr<nsIPowerManagerService> pmService =
-    do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+  nsRefPtr<power::PowerManagerService> pmService =
+    power::PowerManagerService::GetInstance();
   NS_ENSURE_TRUE(pmService, NS_ERROR_FAILURE);
 
   nsString mountLockName;
   vol->GetMountLockName(mountLockName);
-  rv = pmService->NewWakeLock(mountLockName, nullptr, getter_AddRefs(mWakeLock));
-  NS_ENSURE_SUCCESS(rv, rv);
+
+  ErrorResult err;
+  mWakeLock = pmService->NewWakeLock(mountLockName, nullptr, err);
+  if (err.Failed()) {
+    return err.ErrorCode();
+  }
 
   LOG("nsVolumeMountLock acquired for '%s' gen %d",
       NS_LossyConvertUTF16toASCII(mVolumeName).get(), mVolumeGeneration);
diff --git a/dom/system/gonk/nsVolumeMountLock.h b/dom/system/gonk/nsVolumeMountLock.h
index c760c5346ae..b907f950388 100644
--- a/dom/system/gonk/nsVolumeMountLock.h
+++ b/dom/system/gonk/nsVolumeMountLock.h
@@ -7,10 +7,11 @@
 
 #include "nsIVolumeMountLock.h"
 
-#include "nsIDOMWakeLock.h"
+#include "mozilla/dom/WakeLock.h"
 #include "nsIObserver.h"
 #include "nsString.h"
 #include "nsTArray.h"
+#include "nsAutoPtr.h"
 #include "nsWeakReference.h"
 
 namespace mozilla {
@@ -41,10 +42,10 @@ private:
 
   nsresult Init();
 
-  nsString                    mVolumeName;
-  int32_t                     mVolumeGeneration;
-  nsCOMPtr<nsIDOMMozWakeLock> mWakeLock;
-  bool                        mUnlocked;
+  nsRefPtr<dom::WakeLock>  mWakeLock;
+  nsString                 mVolumeName;
+  int32_t                  mVolumeGeneration;
+  bool                     mUnlocked;
 };
 
 } // namespace system
diff --git a/dom/power/nsIDOMWakeLock.idl b/dom/webidl/MozWakeLock.webidl
similarity index 52%
rename from dom/power/nsIDOMWakeLock.idl
rename to dom/webidl/MozWakeLock.webidl
index c83ebd61383..5969e8af0a5 100644
--- a/dom/power/nsIDOMWakeLock.idl
+++ b/dom/webidl/MozWakeLock.webidl
@@ -1,19 +1,18 @@
-/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* -*- Mode: IDL; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+ * 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 "nsISupports.idl"
-
-[scriptable, uuid(2e61eed1-5983-4562-8f26-fd361ab4a00d)]
-interface nsIDOMMozWakeLock : nsISupports
+[Func="Navigator::HasWakeLockSupport"]
+interface MozWakeLock
 {
     readonly attribute DOMString topic;
 
     /**
      * Release the wake lock.
-     *
      * @throw NS_ERROR_DOM_INVALID_STATE_ERR if already unlocked.
      */
+    [Throws]
     void unlock();
 };
diff --git a/dom/webidl/Navigator.webidl b/dom/webidl/Navigator.webidl
index ba12afb796e..a95c3c891fe 100644
--- a/dom/webidl/Navigator.webidl
+++ b/dom/webidl/Navigator.webidl
@@ -17,8 +17,6 @@
  * and create derivative works of this document.
  */
 
-interface MozWakeLock;
-
 // http://www.whatwg.org/specs/web-apps/current-work/#the-navigator-object
 [HeaderFile="Navigator.h", NeedNewResolve]
 interface Navigator {
@@ -193,7 +191,7 @@ partial interface Navigator {
    * One topic can be locked multiple times; it is considered released only when
    * all locks on the topic have been released.
    *
-   * The returned nsIDOMMozWakeLock object is a token of the lock.  You can
+   * The returned MozWakeLock object is a token of the lock.  You can
    * unlock the lock via the object's |unlock| method.  The lock is released
    * automatically when its associated window is unloaded.
    *
diff --git a/dom/webidl/moz.build b/dom/webidl/moz.build
index 039b51c4ab8..5571d05faba 100644
--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -233,6 +233,7 @@ WEBIDL_FILES = [
     'MozNamedAttrMap.webidl',
     'MozPowerManager.webidl',
     'MozTimeManager.webidl',
+    'MozWakeLock.webidl',
     'MutationEvent.webidl',
     'MutationObserver.webidl',
     'NetDashboard.webidl',