Enable Oilpan by default for webaudio/

Source/modules/webaudio/WaveShaperNode.h

Index: Source/modules/webaudio/WaveShaperNode.h
diff --git a/Source/modules/webaudio/WaveShaperNode.h b/Source/modules/webaudio/WaveShaperNode.h
index ff33116ce3cfbcb3b31477755115d79b2a49bf4e..a9f9fe5363ddbe89388dc4d51e3050466ba700c6 100644
--- a/Source/modules/webaudio/WaveShaperNode.h
+++ b/Source/modules/webaudio/WaveShaperNode.h
@@ -36,9 +36,9 @@ class ExceptionState;
 
 class WaveShaperNode FINAL : public AudioBasicProcessorNode {
 public:
-    static PassRefPtrWillBeRawPtr<WaveShaperNode> create(AudioContext* context)
+    static WaveShaperNode* create(AudioContext* context)
     {
-        return adoptRefWillBeNoop(new WaveShaperNode(context));
+        return adoptRefCountedGarbageCollectedWillBeNoop(new WaveShaperNode(context));
     }
 
     // setCurve() is called on the main thread.