Add DCHECK to WebEmbeddedWorkerImpl to assert WebFrameClient params.

third_party/WebKit/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 313 matching lines @@
   CString content("");
   RefPtr<SharedBuffer> buffer(
       SharedBuffer::create(content.data(), content.length()));
   m_loadingShadowPage = true;
   m_mainFrame->frame()->loader().load(
       FrameLoadRequest(0, ResourceRequest(m_workerStartData.scriptURL),
                        SubstituteData(buffer, "text/html", "UTF-8", KURL())));
 }
 
 void WebEmbeddedWorkerImpl::didFinishDocumentLoad(WebLocalFrame* frame) {
+  DCHECK_EQ(frame, m_mainFrame);
   DCHECK(!m_mainScriptLoader);
   DCHECK(m_mainFrame);
   DCHECK(m_workerContextClient);
   DCHECK(m_loadingShadowPage);
   DCHECK(!m_askedToTerminate);
   m_loadingShadowPage = false;
   frame->dataSource()->setServiceWorkerNetworkProvider(WTF::wrapUnique(
       m_workerContextClient->createServiceWorkerNetworkProvider()));
   m_mainScriptLoader = WorkerScriptLoader::create();
   m_mainScriptLoader->setRequestContext(
@@ skipping 126 matching lines @@
       *this, *document, *m_workerContextClient);
   m_loaderProxy = WorkerLoaderProxy::create(this);
   m_workerThread =
       ServiceWorkerThread::create(m_loaderProxy, *m_workerGlobalScopeProxy);
   m_workerThread->start(std::move(startupData), m_mainThreadTaskRunners.get());
   m_workerInspectorProxy->workerThreadCreated(document, m_workerThread.get(),
                                               scriptURL);
 }
 
 }  // namespace blink