Enable Oilpan by default for webaudio/

Source/modules/webaudio/ConvolverNode.h

Index: Source/modules/webaudio/ConvolverNode.h
diff --git a/Source/modules/webaudio/ConvolverNode.h b/Source/modules/webaudio/ConvolverNode.h
index 3cee78271d662646f1bf89d947d3d9fd1e347656..04654b86c554dfaccfb71c5adf9b1c8b6bc58ac0 100644
--- a/Source/modules/webaudio/ConvolverNode.h
+++ b/Source/modules/webaudio/ConvolverNode.h
@@ -38,9 +38,9 @@ class Reverb;
 
 class ConvolverNode FINAL : public AudioNode {
 public:
-    static PassRefPtrWillBeRawPtr<ConvolverNode> create(AudioContext* context, float sampleRate)
+    static ConvolverNode* create(AudioContext* context, float sampleRate)
     {
-        return adoptRefWillBeNoop(new ConvolverNode(context, sampleRate));
+        return adoptRefCountedGarbageCollectedWillBeNoop(new ConvolverNode(context, sampleRate));
     }
 
     virtual ~ConvolverNode();
@@ -67,7 +67,7 @@ private:
     virtual double latencyTime() const OVERRIDE;
 
     OwnPtr<Reverb> m_reverb;
-    RefPtrWillBeMember<AudioBuffer> m_buffer;
+    Member<AudioBuffer> m_buffer;
 
     // This synchronizes dynamic changes to the convolution impulse response with process().
     mutable Mutex m_processLock;