bug 916387 keep ScriptProcessorNode alive after input is GCed r=padenot

--HG--
extra : rebase_source : a9f5d8f4c33845d1548c2daf53d7aced6d6e668b

dom/media/webaudio/ScriptProcessorNode.cpp

@@ -568,8 +568,9 @@ ScriptProcessorNode::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProt
 void
 ScriptProcessorNode::UpdateConnectedStatus()
 {
-  bool isConnected = !(OutputNodes().IsEmpty() && OutputParams().IsEmpty()
-                       && InputNodes().IsEmpty());
+  bool isConnected = mHasPhantomInput ||
+    !(OutputNodes().IsEmpty() && OutputParams().IsEmpty()
+      && InputNodes().IsEmpty());
 
   // Events are queued even when there is no listener because a listener
   // may be added while events are in the queue.

dom/media/webaudio/ScriptProcessorNode.h

@@ -62,6 +62,12 @@ public:
   {
     UpdateConnectedStatus();
   }
+  virtual void NotifyHasPhantomInput() override
+  {
+    mHasPhantomInput = true;
+    // No need to UpdateConnectedStatus() because there was previously an
+    // input in InputNodes().
+  }
 
   virtual void SetChannelCount(uint32_t aChannelCount, ErrorResult& aRv) override
   {
@@ -105,6 +111,7 @@ private:
 
   const uint32_t mBufferSize;
   const uint32_t mNumberOfOutputChannels;
+  bool mHasPhantomInput = false;
 };
 
 } // namespace dom