Pass the v8::Context through the willDestroyServiceWorkerContextOnWorkerThread event.

content/renderer/service_worker/service_worker_context_client.cc

 // Copyright 2015 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/service_worker_context_client.h"
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 371 matching lines @@
   // so that at the time we send it we can be sure that the
   // worker run loop has been started.
   worker_task_runner_->PostTask(
       FROM_HERE, base::Bind(&ServiceWorkerContextClient::SendWorkerStarted,
                             GetWeakPtr()));
 }
 
 void ServiceWorkerContextClient::didInitializeWorkerContext(
     v8::Local<v8::Context> context,
     const blink::WebURL& url) {
-  // TODO(annekao): Remove WebURL parameter from Blink (since url and script_url
-  // are equal). Also remove m_documentURL from ServiceWorkerGlobalScopeProxy.
-  DCHECK_EQ(script_url_, GURL(url));

[not at google - send to devlin, 2015/08/26 01:17:07]

I removed this DCHECK because in order to address the TODO it's more convenient
for it to just ignore |url|. I may do this TODO while I'm here, but not in this
set of patches.

+  // TODO(annekao): Remove WebURL parameter from Blink, it's at best redundant
+  // given |script_url_|, and may be empty in the future.
+  // Also remove m_documentURL from ServiceWorkerGlobalScopeProxy.
   GetContentClient()
       ->renderer()
       ->DidInitializeServiceWorkerContextOnWorkerThread(context, script_url_);
 }
 
-void ServiceWorkerContextClient::willDestroyWorkerContext() {
+void ServiceWorkerContextClient::willDestroyWorkerContext(
+    v8::Local<v8::Context> context) {

[kinuko, 2015/08/26 09:04:18]

Looking into https://codereview.chromium.org/1310843006/ when this one's called
this v8 context may not be already available.  If this is used only as a key to
remove the corresponding extension context could we just use a raw pointer of
this instance or of proxy_?

[not at google - send to devlin, 2015/08/26 17:29:02]

A raw pointer of a v8::Context? How would that help (and also I don't think v8
likes that).

[kinuko, 2015/08/27 00:36:55]

I was thinking about using a pointer to 'this', ServiceWorkerContextClient, or
whatever that can be used to identify this context.

[not at google - send to devlin, 2015/08/27 15:11:50]

I would need to move this into content/public for that to work. v8::Context
seems to work fine + is consistent.

   // At this point OnWorkerRunLoopStopped is already called, so
   // worker_task_runner_->RunsTasksOnCurrentThread() returns false
   // (while we're still on the worker thread).
   proxy_ = NULL;
 
   // We have to clear callbacks now, as they need to be freed on the
   // same thread.
   context_.reset();
 
   // This also lets the message filter stop dispatching messages to
   // this client.
   g_worker_client_tls.Pointer()->Set(NULL);
 
   GetContentClient()->renderer()->WillDestroyServiceWorkerContextOnWorkerThread(
-      script_url_);
+      context, script_url_);
 }
 
 void ServiceWorkerContextClient::workerContextDestroyed() {
   DCHECK(g_worker_client_tls.Pointer()->Get() == NULL);
 
   // Now we should be able to free the WebEmbeddedWorker container on the
   // main thread.
   main_thread_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&CallWorkerContextDestroyedOnMainThread,
@@ skipping 547 matching lines @@
 }
 
 base::WeakPtr<ServiceWorkerContextClient>
 ServiceWorkerContextClient::GetWeakPtr() {
   DCHECK(worker_task_runner_->RunsTasksOnCurrentThread());
   DCHECK(context_);
   return context_->weak_factory.GetWeakPtr();
 }
 
 }  // namespace content