Oilpan: move MessageChannel to the heap.

Source/core/workers/SharedWorker.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 45 matching lines @@
 
 PassRefPtrWillBeRawPtr<SharedWorker> SharedWorker::create(ExecutionContext* context, const String& url, const String& name, ExceptionState& exceptionState)
 {
     ASSERT(isMainThread());
     ASSERT_WITH_SECURITY_IMPLICATION(context->isDocument());
 
     UseCounter::count(context, UseCounter::SharedWorkerStart);
 
     RefPtrWillBeRawPtr<SharedWorker> worker = adoptRefWillBeRefCountedGarbageCollected(new SharedWorker(context));
 
-    RefPtr<MessageChannel> channel = MessageChannel::create(context);
+    RefPtrWillBeRawPtr<MessageChannel> channel = MessageChannel::create(context);
     worker->m_port = channel->port1();
     OwnPtr<blink::WebMessagePortChannel> remotePort = channel->port2()->disentangle();
     ASSERT(remotePort);
 
     worker->suspendIfNeeded();
 
     // We don't currently support nested workers, so workers can only be created from documents.
     Document* document = toDocument(context);
     if (!document->securityOrigin()->canAccessSharedWorkers()) {
         exceptionState.throwSecurityError("Access to shared workers is denied to origin '" + document->securityOrigin()->toString() + "'.");
@@ skipping 29 matching lines @@
     unsetPendingActivity(this);
 }
 
 void SharedWorker::trace(Visitor* visitor)
 {
     AbstractWorker::trace(visitor);
     WillBeHeapSupplementable<SharedWorker>::trace(visitor);
 }
 
 } // namespace WebCore