Enable Oilpan by default for webaudio/

Source/web/WebMediaPlayerClientImpl.h

Index: Source/web/WebMediaPlayerClientImpl.h
diff --git a/Source/web/WebMediaPlayerClientImpl.h b/Source/web/WebMediaPlayerClientImpl.h
index 7e71cb261b37240de649254e833e837f78acda76..82c3b4c5bf71dd9fd14d840560892236020228e9 100644
--- a/Source/web/WebMediaPlayerClientImpl.h
+++ b/Source/web/WebMediaPlayerClientImpl.h
@@ -104,7 +104,7 @@ private:
     // AudioClientImpl wraps an AudioSourceProviderClient.
     // When the audio format is known, Chromium calls setFormat() which then dispatches into WebCore.
 
-    class AudioClientImpl FINAL : public NoBaseWillBeGarbageCollectedFinalized<AudioClientImpl>, public WebAudioSourceProviderClient {
+    class AudioClientImpl FINAL : public GarbageCollectedFinalized<AudioClientImpl>, public WebAudioSourceProviderClient {
     public:
         explicit AudioClientImpl(AudioSourceProviderClient* client)
             : m_client(client)
@@ -119,7 +119,7 @@ private:
         void trace(Visitor*);
 
     private:
-        RawPtrWillBeMember<AudioSourceProviderClient> m_client;
+        Member<AudioSourceProviderClient> m_client;
     };
 
     // AudioSourceProviderImpl wraps a WebAudioSourceProvider.
@@ -143,7 +143,7 @@ private:
 
     private:
         WebAudioSourceProvider* m_webAudioSourceProvider;
-        OwnPtrWillBePersistent<AudioClientImpl> m_client;
+        Persistent<AudioClientImpl> m_client;
         Mutex provideInputLock;
     };