Enable Oilpan by default for webaudio/

Source/modules/webaudio/AudioListener.h

Index: Source/modules/webaudio/AudioListener.h
diff --git a/Source/modules/webaudio/AudioListener.h b/Source/modules/webaudio/AudioListener.h
index 6dbc92d0cab8275bccfd4fa6b4584d4ceced9231..4cb26cdb69d13c97120ce0b24518c2df59d1a8cd 100644
--- a/Source/modules/webaudio/AudioListener.h
+++ b/Source/modules/webaudio/AudioListener.h
@@ -33,7 +33,6 @@
 #include "platform/geometry/FloatPoint3D.h"
 #include "platform/heap/Handle.h"
 #include "wtf/PassRefPtr.h"
-#include "wtf/RefCounted.h"
 #include "wtf/Vector.h"
 
 namespace blink {
@@ -43,11 +42,11 @@ class PannerNode;
 
 // AudioListener maintains the state of the listener in the audio scene as defined in the OpenAL specification.
 
-class AudioListener : public RefCountedWillBeGarbageCollectedFinalized<AudioListener>, public ScriptWrappable {
+class AudioListener : public GarbageCollectedFinalized<AudioListener>, public ScriptWrappable {
 public:
-    static PassRefPtrWillBeRawPtr<AudioListener> create()
+    static AudioListener* create()
     {
-        return adoptRefWillBeNoop(new AudioListener());
+        return new AudioListener();
     }
     virtual ~AudioListener();
 
@@ -109,7 +108,7 @@ private:
     mutable Mutex m_listenerLock;
     // List for pannerNodes in context. This is updated only in the main thread,
     // and can be referred in audio thread.
-    WillBeHeapVector<RawPtrWillBeMember<PannerNode> > m_panners;
+    HeapVector<Member<PannerNode> > m_panners;
     // HRTF DB loader for panner node.
     RefPtr<HRTFDatabaseLoader> m_hrtfDatabaseLoader;
 };