diff --git a/dom/media/MediaDataDecodedListener.h b/dom/media/MediaDataDecodedListener.h
index 2d5e9d0c9942..cbcb67b2c311 100644
--- a/dom/media/MediaDataDecodedListener.h
+++ b/dom/media/MediaDataDecodedListener.h
@@ -20,6 +20,8 @@ class MediaData;
 template<class Target>
 class MediaDataDecodedListener : public RequestSampleCallback {
 public:
+  using RequestSampleCallback::NotDecodedReason;
+
   MediaDataDecodedListener(Target* aTarget,
                            MediaTaskQueue* aTaskQueue)
     : mMonitor("MediaDataDecodedListener")
@@ -50,8 +52,7 @@ public:
     mTaskQueue->Dispatch(task);
   }
 
-  virtual void OnNotDecoded(MediaData::Type aType,
-                            MediaDecoderReader::NotDecodedReason aReason) MOZ_OVERRIDE {
+  virtual void OnNotDecoded(MediaData::Type aType, NotDecodedReason aReason) MOZ_OVERRIDE {
     MonitorAutoLock lock(mMonitor);
     if (!mTarget || !mTaskQueue) {
       // We've been shutdown, abort.
@@ -132,7 +133,7 @@ private:
   class DeliverNotDecodedTask : public nsRunnable {
   public:
     DeliverNotDecodedTask(MediaData::Type aType,
-                          MediaDecoderReader::NotDecodedReason aReason,
+                          RequestSampleCallback::NotDecodedReason aReason,
                           Target* aTarget)
       : mType(aType)
       , mReason(aReason)
@@ -152,7 +153,7 @@ private:
     }
   private:
     MediaData::Type mType;
-    MediaDecoderReader::NotDecodedReason mReason;
+    RequestSampleCallback::NotDecodedReason mReason;
     RefPtr<Target> mTarget;
   };
 
diff --git a/dom/media/MediaDecoderReader.cpp b/dom/media/MediaDecoderReader.cpp
index 1de9b6f12580..e0bdfb389da7 100644
--- a/dom/media/MediaDecoderReader.cpp
+++ b/dom/media/MediaDecoderReader.cpp
@@ -204,7 +204,7 @@ MediaDecoderReader::RequestVideoData(bool aSkipToNextKeyframe,
     }
     GetCallback()->OnVideoDecoded(v);
   } else if (VideoQueue().IsFinished()) {
-    GetCallback()->OnNotDecoded(MediaData::VIDEO_DATA, END_OF_STREAM);
+    GetCallback()->OnNotDecoded(MediaData::VIDEO_DATA, RequestSampleCallback::END_OF_STREAM);
   }
 }
 
@@ -237,7 +237,7 @@ MediaDecoderReader::RequestAudioData()
     GetCallback()->OnAudioDecoded(a);
     return;
   } else if (AudioQueue().IsFinished()) {
-    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, END_OF_STREAM);
+    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, RequestSampleCallback::END_OF_STREAM);
     return;
   }
 }
@@ -307,13 +307,12 @@ AudioDecodeRendezvous::OnAudioDecoded(AudioData* aSample)
 }
 
 void
-AudioDecodeRendezvous::OnNotDecoded(MediaData::Type aType,
-                                    MediaDecoderReader::NotDecodedReason aReason)
+AudioDecodeRendezvous::OnNotDecoded(MediaData::Type aType, NotDecodedReason aReason)
 {
   MOZ_ASSERT(aType == MediaData::AUDIO_DATA);
   MonitorAutoLock mon(mMonitor);
   mSample = nullptr;
-  mStatus = aReason == MediaDecoderReader::DECODE_ERROR ? NS_ERROR_FAILURE : NS_OK;
+  mStatus = aReason == DECODE_ERROR ? NS_ERROR_FAILURE : NS_OK;
   mHaveResult = true;
   mon.NotifyAll();
 }
diff --git a/dom/media/MediaDecoderReader.h b/dom/media/MediaDecoderReader.h
index 508ee8fa8bd7..e759e9d15947 100644
--- a/dom/media/MediaDecoderReader.h
+++ b/dom/media/MediaDecoderReader.h
@@ -30,13 +30,6 @@ class SharedDecoderManager;
 // be accessed on the decode task queue.
 class MediaDecoderReader {
 public:
-  enum NotDecodedReason {
-    END_OF_STREAM,
-    DECODE_ERROR,
-    WAITING_FOR_DATA,
-    CANCELED
-  };
-
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaDecoderReader)
 
   explicit MediaDecoderReader(AbstractMediaDecoder* aDecoder);
@@ -297,6 +290,13 @@ class RequestSampleCallback {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(RequestSampleCallback)
 
+  enum NotDecodedReason {
+    END_OF_STREAM,
+    DECODE_ERROR,
+    WAITING_FOR_DATA,
+    CANCELED
+  };
+
   // Receives the result of a RequestAudioData() call.
   virtual void OnAudioDecoded(AudioData* aSample) = 0;
 
@@ -305,8 +305,7 @@ public:
 
   // Called when a RequestAudioData() or RequestVideoData() call can't be
   // fulfiled. The reason is passed as aReason.
-  virtual void OnNotDecoded(MediaData::Type aType,
-                            MediaDecoderReader::NotDecodedReason aReason) = 0;
+  virtual void OnNotDecoded(MediaData::Type aType, NotDecodedReason aReason) = 0;
 
   virtual void OnSeekCompleted(nsresult aResult) = 0;
 
@@ -323,6 +322,8 @@ protected:
 // model of the MediaDecoderReader to a synchronous model.
 class AudioDecodeRendezvous : public RequestSampleCallback {
 public:
+  using RequestSampleCallback::NotDecodedReason;
+
   AudioDecodeRendezvous();
   ~AudioDecodeRendezvous();
 
@@ -330,8 +331,7 @@ public:
   // Note: aSample is null at end of stream.
   virtual void OnAudioDecoded(AudioData* aSample) MOZ_OVERRIDE;
   virtual void OnVideoDecoded(VideoData* aSample) MOZ_OVERRIDE {}
-  virtual void OnNotDecoded(MediaData::Type aType,
-                            MediaDecoderReader::NotDecodedReason aReason) MOZ_OVERRIDE;
+  virtual void OnNotDecoded(MediaData::Type aType, NotDecodedReason aReason) MOZ_OVERRIDE;
   virtual void OnSeekCompleted(nsresult aResult) MOZ_OVERRIDE {};
   virtual void BreakCycles() MOZ_OVERRIDE {};
   void Reset();
diff --git a/dom/media/MediaDecoderStateMachine.cpp b/dom/media/MediaDecoderStateMachine.cpp
index 0d5b2a8d310d..44376a6a96a5 100644
--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -805,7 +805,7 @@ MediaDecoderStateMachine::Push(VideoData* aSample)
 
 void
 MediaDecoderStateMachine::OnNotDecoded(MediaData::Type aType,
-                                       MediaDecoderReader::NotDecodedReason aReason)
+                                       RequestSampleCallback::NotDecodedReason aReason)
 {
   ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
   SAMPLE_LOG("OnNotDecoded (aType=%u, aReason=%u)", aType, aReason);
@@ -820,7 +820,7 @@ MediaDecoderStateMachine::OnNotDecoded(MediaData::Type aType,
   }
 
   // If this is a decode error, delegate to the generic error path.
-  if (aReason == MediaDecoderReader::DECODE_ERROR) {
+  if (aReason == RequestSampleCallback::DECODE_ERROR) {
     DecodeError();
     return;
   }
@@ -828,7 +828,7 @@ MediaDecoderStateMachine::OnNotDecoded(MediaData::Type aType,
   // If the decoder is waiting for data, we need to make sure that the requests
   // are cleared, which happened above. Additionally, if we're out of decoded
   // samples, we need to switch to buffering mode.
-  if (aReason == MediaDecoderReader::WAITING_FOR_DATA) {
+  if (aReason == RequestSampleCallback::WAITING_FOR_DATA) {
     bool outOfSamples = isAudio ? !AudioQueue().GetSize() : !VideoQueue().GetSize();
     if (outOfSamples) {
       StartBuffering();
@@ -837,14 +837,14 @@ MediaDecoderStateMachine::OnNotDecoded(MediaData::Type aType,
     return;
   }
 
-  if (aReason == MediaDecoderReader::CANCELED) {
+  if (aReason == RequestSampleCallback::CANCELED) {
     DispatchDecodeTasksIfNeeded();
     return;
   }
 
   // This is an EOS. Finish off the queue, and then handle things based on our
   // state.
-  MOZ_ASSERT(aReason == MediaDecoderReader::END_OF_STREAM);
+  MOZ_ASSERT(aReason == RequestSampleCallback::END_OF_STREAM);
   if (!isAudio && mState == DECODER_STATE_SEEKING &&
       mCurrentSeekTarget.IsValid() && mFirstVideoFrameAfterSeek) {
     // Null sample. Hit end of stream. If we have decoded a frame,
diff --git a/dom/media/MediaDecoderStateMachine.h b/dom/media/MediaDecoderStateMachine.h
index 5f23f21c5db6..11609112a0ee 100644
--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -368,7 +368,7 @@ public:
 
   void OnAudioDecoded(AudioData* aSample);
   void OnVideoDecoded(VideoData* aSample);
-  void OnNotDecoded(MediaData::Type aType, MediaDecoderReader::NotDecodedReason aReason);
+  void OnNotDecoded(MediaData::Type aType, RequestSampleCallback::NotDecodedReason aReason);
   void OnSeekCompleted(nsresult aResult);
 
 private:
diff --git a/dom/media/mediasource/MediaSourceReader.cpp b/dom/media/mediasource/MediaSourceReader.cpp
index d6770e640e4b..994ae82547f7 100644
--- a/dom/media/mediasource/MediaSourceReader.cpp
+++ b/dom/media/mediasource/MediaSourceReader.cpp
@@ -100,7 +100,7 @@ MediaSourceReader::RequestAudioData()
   MSE_DEBUGV("MediaSourceReader(%p)::RequestAudioData", this);
   if (!mAudioReader) {
     MSE_DEBUG("MediaSourceReader(%p)::RequestAudioData called with no audio reader", this);
-    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, DECODE_ERROR);
+    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, RequestSampleCallback::DECODE_ERROR);
     return;
   }
   mAudioIsSeeking = false;
@@ -139,7 +139,7 @@ MediaSourceReader::RequestVideoData(bool aSkipToNextKeyframe, int64_t aTimeThres
              this, aSkipToNextKeyframe, aTimeThreshold);
   if (!mVideoReader) {
     MSE_DEBUG("MediaSourceReader(%p)::RequestVideoData called with no video reader", this);
-    GetCallback()->OnNotDecoded(MediaData::VIDEO_DATA, DECODE_ERROR);
+    GetCallback()->OnNotDecoded(MediaData::VIDEO_DATA, RequestSampleCallback::DECODE_ERROR);
     return;
   }
   if (aSkipToNextKeyframe) {
@@ -177,16 +177,17 @@ MediaSourceReader::OnVideoDecoded(VideoData* aSample)
 }
 
 void
-MediaSourceReader::OnNotDecoded(MediaData::Type aType, NotDecodedReason aReason)
+MediaSourceReader::OnNotDecoded(MediaData::Type aType, RequestSampleCallback::NotDecodedReason aReason)
 {
   MSE_DEBUG("MediaSourceReader(%p)::OnNotDecoded aType=%u aReason=%u IsEnded: %d", this, aType, aReason, IsEnded());
-  if (aReason == DECODE_ERROR || aReason == CANCELED) {
+  if (aReason == RequestSampleCallback::DECODE_ERROR ||
+      aReason == RequestSampleCallback::CANCELED) {
     GetCallback()->OnNotDecoded(aType, aReason);
     return;
   }
   // End of stream. Force switching past this stream to another reader by
   // switching to the end of the buffered range.
-  MOZ_ASSERT(aReason == END_OF_STREAM);
+  MOZ_ASSERT(aReason == RequestSampleCallback::END_OF_STREAM);
   nsRefPtr<MediaDecoderReader> reader = aType == MediaData::AUDIO_DATA ?
                                           mAudioReader : mVideoReader;
 
@@ -227,13 +228,13 @@ MediaSourceReader::OnNotDecoded(MediaData::Type aType, NotDecodedReason aReason)
 
   // If the entire MediaSource is done, generate an EndOfStream.
   if (IsEnded()) {
-    GetCallback()->OnNotDecoded(aType, END_OF_STREAM);
+    GetCallback()->OnNotDecoded(aType, RequestSampleCallback::END_OF_STREAM);
     return;
   }
 
   // We don't have the data the caller wants. Tell that we're waiting for JS to
   // give us more data.
-  GetCallback()->OnNotDecoded(aType, WAITING_FOR_DATA);
+  GetCallback()->OnNotDecoded(aType, RequestSampleCallback::WAITING_FOR_DATA);
 }
 
 void
diff --git a/dom/media/mediasource/MediaSourceReader.h b/dom/media/mediasource/MediaSourceReader.h
index fdeb09b21d36..d710dd1d5d3a 100644
--- a/dom/media/mediasource/MediaSourceReader.h
+++ b/dom/media/mediasource/MediaSourceReader.h
@@ -54,7 +54,7 @@ public:
 
   void OnVideoDecoded(VideoData* aSample);
 
-  void OnNotDecoded(MediaData::Type aType, NotDecodedReason aReason);
+  void OnNotDecoded(MediaData::Type aType, RequestSampleCallback::NotDecodedReason aReason);
 
   void OnSeekCompleted(nsresult aResult);
 
diff --git a/dom/media/omx/MediaCodecReader.cpp b/dom/media/omx/MediaCodecReader.cpp
index 634a62ab198c..d13cfac3acf5 100644
--- a/dom/media/omx/MediaCodecReader.cpp
+++ b/dom/media/omx/MediaCodecReader.cpp
@@ -488,7 +488,7 @@ MediaCodecReader::DecodeAudioDataTask()
     }
   }
   if (AudioQueue().AtEndOfStream()) {
-    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, END_OF_STREAM);
+    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, RequestSampleCallback::END_OF_STREAM);
   }
   return result;
 }
@@ -508,7 +508,7 @@ MediaCodecReader::DecodeVideoFrameTask(int64_t aTimeThreshold)
     }
   }
   if (VideoQueue().AtEndOfStream()) {
-    GetCallback()->OnNotDecoded(MediaData::VIDEO_DATA, END_OF_STREAM);
+    GetCallback()->OnNotDecoded(MediaData::VIDEO_DATA, RequestSampleCallback::END_OF_STREAM);
   }
   return result;
 }
diff --git a/dom/media/webm/WebMReader.cpp b/dom/media/webm/WebMReader.cpp
index 5b47c331a1e5..eafa1272d7c1 100644
--- a/dom/media/webm/WebMReader.cpp
+++ b/dom/media/webm/WebMReader.cpp
@@ -743,7 +743,7 @@ bool WebMReader::DecodeOpus(const unsigned char* aData, size_t aLength,
     // Discard padding should be used only on the final packet, so
     // decoding after a padding discard is invalid.
     LOG(PR_LOG_DEBUG, ("Opus error, discard padding on interstitial packet"));
-    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, DECODE_ERROR);
+    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, RequestSampleCallback::DECODE_ERROR);
     return false;
   }
 
@@ -797,7 +797,7 @@ bool WebMReader::DecodeOpus(const unsigned char* aData, size_t aLength,
   if (discardPadding < 0) {
     // Negative discard padding is invalid.
     LOG(PR_LOG_DEBUG, ("Opus error, negative discard padding"));
-    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, DECODE_ERROR);
+    GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, RequestSampleCallback::DECODE_ERROR);
     return false;
   }
   if (discardPadding > 0) {
@@ -810,7 +810,7 @@ bool WebMReader::DecodeOpus(const unsigned char* aData, size_t aLength,
     if (discardFrames.value() > frames) {
       // Discarding more than the entire packet is invalid.
       LOG(PR_LOG_DEBUG, ("Opus error, discard padding larger than packet"));
-      GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, DECODE_ERROR);
+      GetCallback()->OnNotDecoded(MediaData::AUDIO_DATA, RequestSampleCallback::DECODE_ERROR);
       return false;
     }
     LOG(PR_LOG_DEBUG, ("Opus decoder discarding %d of %d frames",