Pass the v8::Context through the willDestroyServiceWorkerContextOnWorkerThread event.

content/renderer/service_worker/service_worker_context_client.cc

Index: content/renderer/service_worker/service_worker_context_client.cc
diff --git a/content/renderer/service_worker/service_worker_context_client.cc b/content/renderer/service_worker/service_worker_context_client.cc
index 55cf381ce034c50eb5c4d170f7a106005cfd49cb..569f6972131ca604161833c29547701a557173b7 100644
--- a/content/renderer/service_worker/service_worker_context_client.cc
+++ b/content/renderer/service_worker/service_worker_context_client.cc
@@ -389,15 +389,16 @@ void ServiceWorkerContextClient::didEvaluateWorkerScript(bool success) {
 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).
@@ -412,7 +413,7 @@ void ServiceWorkerContextClient::willDestroyWorkerContext() {
   g_worker_client_tls.Pointer()->Set(NULL);
 
   GetContentClient()->renderer()->WillDestroyServiceWorkerContextOnWorkerThread(
-      script_url_);
+      context, script_url_);
 }
 
 void ServiceWorkerContextClient::workerContextDestroyed() {