Bug 1071482 - Break a cycle in TrackBuffer and SourceBufferDecoder's MediaTaskQueue's SharedThreadPool. r=cajbir

dom/media/mediasource/SourceBufferDecoder.h

@@ -84,6 +84,18 @@ public:
     mTaskQueue = aTaskQueue;
   }
 
+  void BreakCycles()
+  {
+    if (mReader) {
+      mReader->BreakCycles();
+      mReader = nullptr;
+    }
+    mTaskQueue = nullptr;
+#ifdef MOZ_EME
+    mCDMProxy = nullptr;
+#endif
+  }
+
 #ifdef MOZ_EME
   virtual nsresult SetCDMProxy(CDMProxy* aProxy)
   {

dom/media/mediasource/TrackBuffer.cpp

@@ -391,7 +391,7 @@ TrackBuffer::BreakCycles()
   MOZ_ASSERT(NS_IsMainThread());
 
   for (uint32_t i = 0; i < mDecoders.Length(); ++i) {
-    mDecoders[i]->GetReader()->BreakCycles();
+    mDecoders[i]->BreakCycles();
   }
   mDecoders.Clear();