ServiceWorker: Drop statechange events if WebServiceWorkerProxy is not ready

content/child/service_worker/web_service_worker_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/service_worker/web_service_worker_impl.h"
 
 #include "content/child/service_worker/service_worker_dispatcher.h"
 #include "content/child/service_worker/service_worker_handle_reference.h"
 #include "content/child/thread_safe_sender.h"
 #include "content/child/webmessageportchannel_impl.h"
@@ skipping 40 matching lines @@
     return;
   ServiceWorkerDispatcher* dispatcher =
       ServiceWorkerDispatcher::GetThreadSpecificInstance();
   if (dispatcher)
     dispatcher->RemoveServiceWorker(handle_ref_->handle_id());
 }
 
 void WebServiceWorkerImpl::OnStateChanged(
     blink::WebServiceWorkerState new_state) {
   state_ = new_state;
-  proxy_->dispatchStateChangeEvent();
+
+  // TODO(nhiroki): This is a quick fix for http://crbug.com/507110
+  DCHECK(proxy_);
+  if (proxy_)
+    proxy_->dispatchStateChangeEvent();
 }
 
 void WebServiceWorkerImpl::setProxy(blink::WebServiceWorkerProxy* proxy) {
   proxy_ = proxy;
 }
 
 blink::WebServiceWorkerProxy* WebServiceWorkerImpl::proxy() {
   return proxy_;
 }
 
@@ skipping 23 matching lines @@
                             static_cast<base::string16>(message),
                             base::Passed(make_scoped_ptr(channels))));
 }
 
 void WebServiceWorkerImpl::terminate() {
   thread_safe_sender_->Send(
       new ServiceWorkerHostMsg_TerminateWorker(handle_ref_->handle_id()));
 }
 
 }  // namespace content