Backed out changeset 2938c2e1f7e7 (bug 867203) since part 1 had to be backed out for conflicts

content/media/webaudio/AudioBufferSourceNode.cpp

@@ -412,6 +412,7 @@ AudioBufferSourceNode::AudioBufferSourceNode(AudioContext* aContext)
   , mOffset(0.0)
   , mDuration(std::numeric_limits<double>::min())
   , mPlaybackRate(new AudioParam(this, SendPlaybackRateToStream, 1.0f))
+  , mPannerNode(nullptr)
   , mLoop(false)
   , mStartCalled(false)
   , mOffsetAndDurationRemembered(false)

content/media/webaudio/AudioBufferSourceNode.h

@@ -37,6 +37,15 @@ public:
   {
     return this;
   }
+
+  void UnregisterPannerNode() {
+    mPannerNode = nullptr;
+  }
+
+  void RegisterPannerNode(PannerNode* aPannerNode) {
+    mPannerNode = aPannerNode;
+  }
+
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AudioBufferSourceNode, AudioNode)
 
@@ -139,6 +148,7 @@ private:
   double mDuration;
   nsRefPtr<AudioBuffer> mBuffer;
   nsRefPtr<AudioParam> mPlaybackRate;
+  PannerNode* mPannerNode;
   SelfReference<AudioBufferSourceNode> mPlayingRef; // a reference to self while playing
   bool mLoop;
   bool mStartCalled;

content/media/webaudio/AudioContext.cpp

@@ -258,6 +258,13 @@ AudioContext::UnregisterScriptProcessorNode(ScriptProcessorNode* aNode)
   mScriptProcessorNodes.RemoveEntry(aNode);
 }
 
+static PLDHashOperator
+UnregisterPannerNodeOn(nsPtrHashKey<AudioBufferSourceNode>* aEntry, void* aData)
+{
+  aEntry->GetKey()->UnregisterPannerNode();
+  return PL_DHASH_NEXT;
+}
+
 static PLDHashOperator
 FindConnectedSourcesOn(nsPtrHashKey<PannerNode>* aEntry, void* aData)
 {
@@ -268,6 +275,7 @@ FindConnectedSourcesOn(nsPtrHashKey<PannerNode>* aEntry, void* aData)
 void
 AudioContext::UpdatePannerSource()
 {
+  mAudioBufferSourceNodes.EnumerateEntries(UnregisterPannerNodeOn, nullptr);
   mPannerNodes.EnumerateEntries(FindConnectedSourcesOn, nullptr);
 }
 

content/media/webaudio/PannerNode.cpp

@@ -482,6 +482,9 @@ PannerNode::FindConnectedSources()
   mSources.Clear();
   std::set<AudioNode*> cycleSet;
   FindConnectedSources(this, mSources, cycleSet);
+  for (unsigned i = 0; i < mSources.Length(); i++) {
+    mSources[i]->RegisterPannerNode(this);
+  }
 }
 
 void