Oilpan: move core/workers to oilpan's heap.

Source/core/workers/Worker.cpp

 /*
  * Copyright (C) 2008, 2010 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 Google 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 32 matching lines @@
 
 namespace WebCore {
 
 inline Worker::Worker(ExecutionContext* context)
     : AbstractWorker(context)
     , m_contextProxy(0)
 {
     ScriptWrappable::init(this);
 }
 
-PassRefPtr<Worker> Worker::create(ExecutionContext* context, const String& url, ExceptionState& exceptionState)
+PassRefPtrWillBeRawPtr<Worker> Worker::create(ExecutionContext* context, const String& url, ExceptionState& exceptionState)
 {
     ASSERT(isMainThread());
     Document* document = toDocument(context);
     UseCounter::count(context, UseCounter::WorkerStart);
     if (!document->page()) {
         exceptionState.throwDOMException(InvalidAccessError, "The context provided is invalid.");
         return nullptr;
     }
     WorkerGlobalScopeProxyProvider* proxyProvider = WorkerGlobalScopeProxyProvider::from(*document->page());
     ASSERT(proxyProvider);
 
-    RefPtr<Worker> worker = adoptRef(new Worker(context));
+    RefPtrWillBeRawPtr<Worker> worker = adoptRefCountedWillBeRefCountedGarbageCollected(new Worker(context));
 
     worker->suspendIfNeeded();
 
     KURL scriptURL = worker->resolveURL(url, exceptionState);
     if (scriptURL.isEmpty())
         return nullptr;
 
     // The worker context does not exist while loading, so we must ensure that the worker object is not collected, nor are its event listeners.
     worker->setPendingActivity(worker.get());
 
@@ skipping 20 matching lines @@
 {
     // Disentangle the port in preparation for sending it to the remote context.
     OwnPtr<MessagePortChannelArray> channels = MessagePort::disentanglePorts(ports, exceptionState);
     if (exceptionState.hadException())
         return;
     m_contextProxy->postMessageToWorkerGlobalScope(message, channels.release());
 }
 
 void Worker::terminate()
 {
-    m_contextProxy->terminateWorkerGlobalScope();
+    // NOTE: oilpan: if the Worker fails to fully construct (e.g., invalid URL),

[sof, 2014/02/24 12:53:29]

I'll remove this comment before finalizing; just wanted to give context to a
seemingly random change.

+    // it'll be without a 'context proxy' object but in the heap. If the document
+    // is detached prior to the next GC, it stops active DOM objects, which
+    // will run into a null ptr crash here. Hence, the need for the check.
+    if (m_contextProxy)
+        m_contextProxy->terminateWorkerGlobalScope();

[haraken, 2014/02/24 13:28:36]

Don't you need to clear m_contextProxy in terminate()? Otherwise, m_contextProxy
will become a stale pointer when Worker outlives the context.

 }
 
 void Worker::stop()
 {
     terminate();
 }
 
 bool Worker::hasPendingActivity() const
 {
     return m_contextProxy->hasPendingActivity() || ActiveDOMObject::hasPendingActivity();
@@ skipping 13 matching lines @@
         if (InspectorInstrumentation::shouldPauseDedicatedWorkerOnStart(executionContext()))
             startMode = PauseWorkerGlobalScopeOnStart;
         m_contextProxy->startWorkerGlobalScope(m_scriptLoader->url(), executionContext()->userAgent(m_scriptLoader->url()), m_scriptLoader->script(), startMode);
         InspectorInstrumentation::scriptImported(executionContext(), m_scriptLoader->identifier(), m_scriptLoader->script());
     }
     m_scriptLoader = nullptr;
 
     unsetPendingActivity(this);
 }
 
+void Worker::trace(Visitor* visitor)
+{
+    visitor->trace(m_scriptLoader);
+}
+
 } // namespace WebCore