Oilpan: WebAudio: Prepare to move AudioProcessor hierarchy to Oilpan heap.

Source/modules/webaudio/AudioBasicProcessorNode.h

Index: Source/modules/webaudio/AudioBasicProcessorNode.h
diff --git a/Source/modules/webaudio/AudioBasicProcessorNode.h b/Source/modules/webaudio/AudioBasicProcessorNode.h
index 69a36168eafd47279488e648d4f4b1311d461433..8799b8b52172b1760b3a0d6d0af827a24ffd85d1 100644
--- a/Source/modules/webaudio/AudioBasicProcessorNode.h
+++ b/Source/modules/webaudio/AudioBasicProcessorNode.h
@@ -39,6 +39,7 @@ class AudioProcessor;
 class AudioBasicProcessorNode : public AudioNode {
 public:
     AudioBasicProcessorNode(AudioContext*, float sampleRate);
+    virtual void trace(Visitor*) OVERRIDE;
 
     // AudioNode
     virtual void process(size_t framesToProcess) OVERRIDE FINAL;
@@ -57,7 +58,7 @@ protected:
     virtual double latencyTime() const OVERRIDE FINAL;
 
     AudioProcessor* processor() { return m_processor.get(); }
-    OwnPtr<AudioProcessor> m_processor;
+    OwnPtrWillBeMember<AudioProcessor> m_processor;
 };
 
 } // namespace blink