Expose the ServiceWorker's v8 context to embedders.

Source/web/WebEmbeddedWorkerImpl.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 151 matching lines @@
 {
     ASSERT(m_webView);
 
     // Detach the client before closing the view to avoid getting called back.
     toWebLocalFrameImpl(m_mainFrame)->setClient(0);
 
     m_webView->close();
     m_mainFrame->close();
 }
 
+void WebEmbeddedWorkerImpl::postTask(PassOwnPtr<ExecutionContextTask> task)

[Jeffrey Yasskin, 2014/07/16 23:14:58]

This is again used by the test.

In Content, this purpose is served by
WorkerTaskRunner::PostTask(worker_thread_id), so it probably won't need to be
exposed from the Blink API. That mechanism works by recording all WorkerRunLoops
into a global variable in BlinkPlatformImpl::didStartWorkerRunLoop().

+{
+    // We don't propagate the bool return because |true| doesn't mean the task will be run.
+    m_workerThread->runLoop().postTask(task);
+}
+
 void WebEmbeddedWorkerImpl::startWorkerContext(
     const WebEmbeddedWorkerStartData& data)
 {
     ASSERT(!m_askedToTerminate);
     ASSERT(!m_mainScriptLoader);
     ASSERT(m_pauseAfterDownloadState == DontPauseAfterDownload);
     m_workerStartData = data;
     if (data.pauseAfterDownloadMode == WebEmbeddedWorkerStartData::PauseAfterDownload)
         m_pauseAfterDownloadState = DoPauseAfterDownload;
     prepareShadowPageForLoader();
@@ skipping 177 matching lines @@
     m_mainScriptLoader.clear();
 
     m_workerGlobalScopeProxy = ServiceWorkerGlobalScopeProxy::create(*this, *toWebLocalFrameImpl(m_mainFrame)->frame()->document(), *m_workerContextClient);
     m_loaderProxy = LoaderProxy::create(*this);
 
     m_workerThread = ServiceWorkerThread::create(*m_loaderProxy, *m_workerGlobalScopeProxy, startupData.release());
     m_workerThread->start();
 }
 
 } // namespace blink