Oilpan: put MessageChannel on the heap.

Source/core/dom/MessageChannel.h

Index: Source/core/dom/MessageChannel.h
diff --git a/Source/core/dom/MessageChannel.h b/Source/core/dom/MessageChannel.h
index 62857c0e0ac76cd2fab979b0c9d008186c45e20d..4f0ccfe6c571914db4ea8fd807f9b8a301f2843d 100644
--- a/Source/core/dom/MessageChannel.h
+++ b/Source/core/dom/MessageChannel.h
@@ -29,8 +29,6 @@
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "platform/heap/Handle.h"
-#include "wtf/PassRefPtr.h"
-#include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
@@ -38,13 +36,13 @@ namespace blink {
 class MessagePort;
 class ExecutionContext;
 
-class MessageChannel final : public RefCountedWillBeGarbageCollected<MessageChannel>, public ScriptWrappable {
+class MessageChannel final : public GarbageCollectedFinalized<MessageChannel>, public ScriptWrappable {
     DECLARE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(MessageChannel);
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static PassRefPtrWillBeRawPtr<MessageChannel> create(ExecutionContext* context)
+    static MessageChannel* create(ExecutionContext* context)
     {
-        return adoptRefWillBeNoop(new MessageChannel(context));
+        return new MessageChannel(context);
     }
 
     MessagePort* port1() const { return m_port1.get(); }