Bug 1423241 - Return appended StreamTime samples appended through AppendToTrack. r=padenot

This allows DecodedStream to accurately track how many samples have been
appended to a track, even with resampling enabled.

Differential Revision: https://phabricator.services.mozilla.com/D12272

--HG--
extra : moz-landing-system : lando

dom/media/MediaStreamGraph.cpp

@@ -2863,11 +2863,11 @@ void SourceMediaStream::AdvanceTimeVaryingValuesToCurrentTime(
   mTracks.ForgetUpTo(aCurrentTime - mTracksStartTime);
 }
 
-bool SourceMediaStream::AppendToTrack(TrackID aID, MediaSegment* aSegment,
+StreamTime SourceMediaStream::AppendToTrack(TrackID aID, MediaSegment* aSegment,
                                             MediaSegment* aRawSegment) {
   MutexAutoLock lock(mMutex);
   // ::EndAllTrackAndFinished() can end these before the sources notice
-  bool appended = false;
+  StreamTime appended = 0;
   auto graph = GraphImpl();
   if (!mFinished && graph) {
     TrackData* track = FindDataForTrack(aID);
@@ -2886,8 +2886,8 @@ bool SourceMediaStream::AppendToTrack(TrackID aID, MediaSegment* aSegment,
 
       // Must notify first, since AppendFrom() will empty out aSegment
       NotifyDirectConsumers(track, aRawSegment ? aRawSegment : aSegment);
+      appended = aSegment->GetDuration();
       track->mData->AppendFrom(aSegment);  // note: aSegment is now dead
-      appended = true;
       GraphImpl()->EnsureNextIteration();
     } else {
       aSegment->Clear();

dom/media/MediaStreamGraph.h

@@ -743,10 +743,11 @@ class SourceMediaStream : public MediaStream {
 
   /**
    * Append media data to a track. Ownership of aSegment remains with the
-   * caller, but aSegment is emptied. Returns false if the data was not appended
-   * because no such track exists or the stream was already finished.
+   * caller, but aSegment is emptied. Returns 0 if the data was not appended
+   * because no such track exists or the stream was already finished. Returns
+   * the duration of the appended data in the graph's track rate otherwise.
    */
-  virtual bool AppendToTrack(TrackID aID, MediaSegment* aSegment,
+  virtual StreamTime AppendToTrack(TrackID aID, MediaSegment* aSegment,
                                    MediaSegment* aRawSegment = nullptr);
   /**
    * Get the stream time of the end of the data that has been appended so far.

media/webrtc/signaling/gtest/mediapipeline_unittest.cpp

@@ -52,9 +52,9 @@ public:
     mMainThreadDestroyed = true;
   }
 
-  virtual bool AppendToTrack(TrackID aID, MediaSegment* aSegment, MediaSegment *aRawSegment = nullptr) override
+  virtual StreamTime AppendToTrack(TrackID aID, MediaSegment* aSegment, MediaSegment *aRawSegment = nullptr) override
   {
-    return true;
+    return aSegment->GetDuration();
   }
 };