Tried to move AudioSummingJuction to oilpan

Source/modules/webaudio/OfflineAudioContext.h

Index: Source/modules/webaudio/OfflineAudioContext.h
diff --git a/Source/modules/webaudio/OfflineAudioContext.h b/Source/modules/webaudio/OfflineAudioContext.h
index 31d2a361c5dccc3c19ab2b63c265727eede45ff3..6434069a4c93b45d09ea35c224eaea44b8c72576 100644
--- a/Source/modules/webaudio/OfflineAudioContext.h
+++ b/Source/modules/webaudio/OfflineAudioContext.h
@@ -33,7 +33,7 @@ class ExceptionState;
 
 class OfflineAudioContext FINAL : public AudioContext {
 public:
-    static PassRefPtr<OfflineAudioContext> create(ExecutionContext*, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate, ExceptionState&);
+    static PassRefPtrWillBeRawPtr<OfflineAudioContext> create(ExecutionContext*, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate, ExceptionState&);
 
     virtual ~OfflineAudioContext();