Bug 943461. Part 13: Keep producing silence in AudioNodeStreams' mLastChunks even after they've finished r=padenot

Without this the last before-finished audio block gets picked up by downstream
ObtainInputBlock calls.

--HG--
extra : rebase_source : d7f804cea59454bdb0aa5931d19bcc123e0d16cb

content/media/AudioNodeStream.cpp

@@ -269,8 +269,7 @@ AudioNodeStream::ObtainInputBlock(AudioChunk& aTmpChunk, uint32_t aPortIndex)
     MediaStream* s = mInputs[i]->GetSource();
     AudioNodeStream* a = static_cast<AudioNodeStream*>(s);
     MOZ_ASSERT(a == s->AsAudioNodeStream());
-    if (a->IsFinishedOnGraphThread() ||
-        a->IsAudioParamStream()) {
+    if (a->IsAudioParamStream()) {
       continue;
     }
 
@@ -408,7 +407,7 @@ AudioNodeStream::ProduceOutput(GraphTime aFrom, GraphTime aTo, uint32_t aFlags)
   uint16_t outputCount = std::max(uint16_t(1), mEngine->OutputCount());
   mLastChunks.SetLength(outputCount);
 
-  if (mMuted) {
+  if (mMuted || IsFinishedOnGraphThread()) {
     for (uint16_t i = 0; i < outputCount; ++i) {
       mLastChunks[i].SetNull(WEBAUDIO_BLOCK_SIZE);
     }

content/media/MediaStreamGraph.cpp

@@ -1189,7 +1189,7 @@ MediaStreamGraphImpl::RunThread()
     // Figure out what each stream wants to do
     for (uint32_t i = 0; i < mStreams.Length(); ++i) {
       MediaStream* stream = mStreams[i];
-      if (!doneAllProducing && !stream->IsFinishedOnGraphThread()) {
+      if (!doneAllProducing) {
         ProcessedMediaStream* ps = stream->AsProcessedStream();
         if (ps) {
           AudioNodeStream* n = stream->AsAudioNodeStream();

content/media/MediaStreamGraph.h

@@ -959,7 +959,9 @@ public:
    * Also, we've produced output for all streams up to this one. If this stream
    * is not in a cycle, then all its source streams have produced data.
    * Generate output from aFrom to aTo.
-   * This is called only on streams that have not finished.
+   * This will be called on streams that have finished. Most stream types should
+   * just return immediately if IsFinishedOnGraphThread(), but some may wish to
+   * update internal state (see AudioNodeStream).
    * ProduceOutput is allowed to call FinishOnGraphThread only if ALLOW_FINISH
    * is in aFlags. (This flag will be set when aTo >= mStateComputedTime, i.e.
    * when we've producing the last block of data we need to produce.) Otherwise

content/media/TrackUnionStream.h

@@ -41,6 +41,9 @@ public:
   }
   virtual void ProduceOutput(GraphTime aFrom, GraphTime aTo, uint32_t aFlags) MOZ_OVERRIDE
   {
+    if (IsFinishedOnGraphThread()) {
+      return;
+    }
     nsAutoTArray<bool,8> mappedTracksFinished;
     nsAutoTArray<bool,8> mappedTracksWithMatchingInputTracks;
     for (uint32_t i = 0; i < mTrackMap.Length(); ++i) {