service worker: Attempt to send WorkerStopped before ProviderDestroyed.

content/renderer/service_worker/embedded_worker_dispatcher.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/renderer/service_worker/embedded_worker_dispatcher.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/metrics/histogram_macros.h"
@@ skipping 40 matching lines @@
                         OnResumeAfterDownload)
     IPC_MESSAGE_HANDLER(EmbeddedWorkerMsg_AddMessageToConsole,
                         OnAddMessageToConsole)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void EmbeddedWorkerDispatcher::WorkerContextDestroyed(
     int embedded_worker_id) {
-  UnregisterWorker(embedded_worker_id);
   RenderThreadImpl::current()->thread_safe_sender()->Send(
       new EmbeddedWorkerHostMsg_WorkerStopped(embedded_worker_id));
+  UnregisterWorker(embedded_worker_id);
 }
 
 void EmbeddedWorkerDispatcher::OnStartWorker(
     const EmbeddedWorkerStartParams& params) {
   DCHECK(!workers_.Lookup(params.embedded_worker_id));
   TRACE_EVENT0("ServiceWorker", "EmbeddedWorkerDispatcher::OnStartWorker");
   std::unique_ptr<WorkerWrapper> wrapper = StartWorkerContext(
       params, base::MakeUnique<ServiceWorkerContextClient>(
                   params.embedded_worker_id, params.service_worker_version_id,
                   params.scope, params.script_url,
@@ skipping 100 matching lines @@
 void EmbeddedWorkerDispatcher::RecordStopWorkerTimer(int embedded_worker_id) {
   WorkerWrapper* wrapper = workers_.Lookup(embedded_worker_id);
   DCHECK(wrapper);
   // This should eventually call WorkerContextDestroyed. (We may need to post
   // a delayed task to forcibly abort the worker context if we find it
   // necessary)
   stop_worker_times_[embedded_worker_id] = base::TimeTicks::Now();
 }
 
 }  // namespace content