diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index ed1a41bde28f..e7f20217ff63 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -3124,12 +3124,11 @@ private:
 };
 
 class HTMLMediaElement::MediaStreamTracksAvailableCallback:
-    public DOMMediaStream::OnTracksAvailableCallback
+  public OnTracksAvailableCallback
 {
 public:
   explicit MediaStreamTracksAvailableCallback(HTMLMediaElement* aElement):
-      DOMMediaStream::OnTracksAvailableCallback(),
-      mElement(aElement)
+      OnTracksAvailableCallback(), mElement(aElement)
     {}
   virtual void NotifyTracksAvailable(DOMMediaStream* aStream)
   {
diff --git a/dom/media/DOMMediaStream.h b/dom/media/DOMMediaStream.h
index 00e1d905730e..b7366171c176 100644
--- a/dom/media/DOMMediaStream.h
+++ b/dom/media/DOMMediaStream.h
@@ -33,6 +33,7 @@ namespace mozilla {
 
 class DOMHwMediaStream;
 class DOMLocalMediaStream;
+class DOMMediaStream;
 class MediaStream;
 class MediaEngineSource;
 class MediaInputPort;
@@ -64,6 +65,12 @@ class MediaStreamDirectListener;
 { 0x8cb65468, 0x66c0, 0x444e, \
   { 0x89, 0x9f, 0x89, 0x1d, 0x9e, 0xd2, 0xbe, 0x7c } }
 
+class OnTracksAvailableCallback {
+public:
+  virtual ~OnTracksAvailableCallback() {}
+  virtual void NotifyTracksAvailable(DOMMediaStream* aStream) = 0;
+};
+
 /**
  * DOM wrapper for MediaStreams.
  *
@@ -478,11 +485,6 @@ public:
    */
   MediaStreamTrack* CreateOwnDOMTrack(TrackID aTrackID, MediaSegment::Type aType, const nsString& aLabel);
 
-  class OnTracksAvailableCallback {
-  public:
-    virtual ~OnTracksAvailableCallback() {}
-    virtual void NotifyTracksAvailable(DOMMediaStream* aStream) = 0;
-  };
   // When the initial set of tracks has been added, run
   // aCallback->NotifyTracksAvailable.
   // It is allowed to do anything, including run script.
diff --git a/dom/media/MediaManager.cpp b/dom/media/MediaManager.cpp
index 40f76a04c5df..5ac5bd8455f1 100644
--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -251,7 +251,7 @@ public:
   MediaOperationTask(MediaOperation aType,
     GetUserMediaCallbackMediaStreamListener* aListener,
     DOMMediaStream* aStream,
-    DOMMediaStream::OnTracksAvailableCallback* aOnTracksAvailableCallback,
+    OnTracksAvailableCallback* aOnTracksAvailableCallback,
     AudioDevice* aAudioDevice,
     VideoDevice* aVideoDevice,
     bool aBool,
@@ -378,7 +378,7 @@ public:
 private:
   MediaOperation mType;
   RefPtr<DOMMediaStream> mStream;
-  nsAutoPtr<DOMMediaStream::OnTracksAvailableCallback> mOnTracksAvailableCallback;
+  nsAutoPtr<OnTracksAvailableCallback> mOnTracksAvailableCallback;
   RefPtr<AudioDevice> mAudioDevice; // threadsafe
   RefPtr<VideoDevice> mVideoDevice; // threadsafe
   RefPtr<GetUserMediaCallbackMediaStreamListener> mListener; // threadsafe
@@ -886,7 +886,7 @@ public:
 
   ~GetUserMediaStreamRunnable() {}
 
-  class TracksAvailableCallback : public DOMMediaStream::OnTracksAvailableCallback
+  class TracksAvailableCallback : public OnTracksAvailableCallback
   {
   public:
     TracksAvailableCallback(MediaManager* aManager,
diff --git a/dom/media/MediaManager.h b/dom/media/MediaManager.h
index fbc9891c2e3f..ac0dd422ea4e 100644
--- a/dom/media/MediaManager.h
+++ b/dom/media/MediaManager.h
@@ -350,7 +350,7 @@ class GetUserMediaNotificationEvent: public nsRunnable
 
     GetUserMediaNotificationEvent(GetUserMediaStatus aStatus,
                                   already_AddRefed<DOMMediaStream> aStream,
-                                  DOMMediaStream::OnTracksAvailableCallback* aOnTracksAvailableCallback,
+                                  OnTracksAvailableCallback* aOnTracksAvailableCallback,
                                   bool aIsAudio, bool aIsVideo, uint64_t aWindowID,
                                   already_AddRefed<nsIDOMGetUserMediaErrorCallback> aError)
     : mStream(aStream), mOnTracksAvailableCallback(aOnTracksAvailableCallback),
@@ -366,7 +366,7 @@ class GetUserMediaNotificationEvent: public nsRunnable
   protected:
     RefPtr<GetUserMediaCallbackMediaStreamListener> mListener; // threadsafe
     RefPtr<DOMMediaStream> mStream;
-    nsAutoPtr<DOMMediaStream::OnTracksAvailableCallback> mOnTracksAvailableCallback;
+    nsAutoPtr<OnTracksAvailableCallback> mOnTracksAvailableCallback;
     GetUserMediaStatus mStatus;
     bool mIsAudio;
     bool mIsVideo;
@@ -388,13 +388,13 @@ class ReleaseMediaOperationResource : public nsRunnable
 {
 public:
   ReleaseMediaOperationResource(already_AddRefed<DOMMediaStream> aStream,
-    DOMMediaStream::OnTracksAvailableCallback* aOnTracksAvailableCallback):
+    OnTracksAvailableCallback* aOnTracksAvailableCallback):
     mStream(aStream),
     mOnTracksAvailableCallback(aOnTracksAvailableCallback) {}
   NS_IMETHOD Run() override {return NS_OK;}
 private:
   RefPtr<DOMMediaStream> mStream;
-  nsAutoPtr<DOMMediaStream::OnTracksAvailableCallback> mOnTracksAvailableCallback;
+  nsAutoPtr<OnTracksAvailableCallback> mOnTracksAvailableCallback;
 };
 
 typedef nsTArray<RefPtr<GetUserMediaCallbackMediaStreamListener> > StreamListeners;
diff --git a/dom/media/MediaRecorder.cpp b/dom/media/MediaRecorder.cpp
index c2ed36a57f75..f699cc3a5566 100644
--- a/dom/media/MediaRecorder.cpp
+++ b/dom/media/MediaRecorder.cpp
@@ -288,7 +288,7 @@ class MediaRecorder::Session: public nsIObserver
   };
 
   // For Ensure recorder has tracks to record.
-  class TracksAvailableCallback : public DOMMediaStream::OnTracksAvailableCallback
+  class TracksAvailableCallback : public OnTracksAvailableCallback
   {
   public:
     explicit TracksAvailableCallback(Session *aSession)
diff --git a/media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp b/media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp
index e17f510d3a71..8326c601d410 100644
--- a/media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp
+++ b/media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp
@@ -172,14 +172,14 @@ private:
 }
 
 #if !defined(MOZILLA_EXTERNAL_LINKAGE)
-class TracksAvailableCallback : public DOMMediaStream::OnTracksAvailableCallback
+class TracksAvailableCallback : public OnTracksAvailableCallback
 {
 public:
   TracksAvailableCallback(size_t numNewAudioTracks,
                           size_t numNewVideoTracks,
                           const std::string& pcHandle,
                           RefPtr<PeerConnectionObserver> aObserver)
-  : DOMMediaStream::OnTracksAvailableCallback()
+  : OnTracksAvailableCallback()
   , mObserver(aObserver)
   , mPcHandle(pcHandle)
   {}