Oilpan: move platform speech objects to the heap.

Source/modules/speech/SpeechSynthesisUtterance.h

Index: Source/modules/speech/SpeechSynthesisUtterance.h
diff --git a/Source/modules/speech/SpeechSynthesisUtterance.h b/Source/modules/speech/SpeechSynthesisUtterance.h
index fea86980577d1895b4a763c82354b6114380490b..c1eb9817ae092b9fe6c0c145c866b4ed48edf6d7 100644
--- a/Source/modules/speech/SpeechSynthesisUtterance.h
+++ b/Source/modules/speech/SpeechSynthesisUtterance.h
@@ -38,7 +38,7 @@ namespace WebCore {
 
 class SpeechSynthesisUtterance FINAL : public RefCountedGarbageCollectedWillBeGarbageCollectedFinalized<SpeechSynthesisUtterance>, public PlatformSpeechSynthesisUtteranceClient, public ScriptWrappable, public ContextLifecycleObserver, public EventTargetWithInlineData {
     DEFINE_EVENT_TARGET_REFCOUNTING_WILL_BE_REMOVED(RefCountedGarbageCollected<SpeechSynthesisUtterance>);
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SpeechSynthesisUtterance);
+    USING_GARBAGE_COLLECTED_MIXIN(SpeechSynthesisUtterance);
 public:
     static SpeechSynthesisUtterance* create(ExecutionContext*, const String&);
 
@@ -75,13 +75,13 @@ public:
 
     virtual ExecutionContext* executionContext() const OVERRIDE;
 
-    PlatformSpeechSynthesisUtterance* platformUtterance() const { return m_platformUtterance.get(); }
+    PlatformSpeechSynthesisUtterance* platformUtterance() const { return m_platformUtterance; }
 
     virtual void trace(Visitor*) OVERRIDE;
 
 private:
     SpeechSynthesisUtterance(ExecutionContext*, const String&);
-    RefPtr<PlatformSpeechSynthesisUtterance> m_platformUtterance;
+    Member<PlatformSpeechSynthesisUtterance> m_platformUtterance;
     Member<SpeechSynthesisVoice> m_voice;
 
     // EventTarget