ServiceWorker: Add support for .skipWaiting and controllerchange event(2/3)

content/browser/service_worker/service_worker_provider_host.cc

Index: content/browser/service_worker/service_worker_provider_host.cc
diff --git a/content/browser/service_worker/service_worker_provider_host.cc b/content/browser/service_worker/service_worker_provider_host.cc
index e16454558e0ec9cc46862b3110a811dcf3bfca6f..f18e2dd38ad5dd01162de1f6771d744e6a87cfd1 100644
--- a/content/browser/service_worker/service_worker_provider_host.cc
+++ b/content/browser/service_worker/service_worker_provider_host.cc
@@ -55,6 +55,17 @@ void ServiceWorkerProviderHost::OnRegistrationFailed(
   DisassociateRegistration();
 }
 
+void ServiceWorkerProviderHost::OnSkippedWaiting(
+    ServiceWorkerRegistration* registration) {
+  CHECK_EQ(associated_registration_.get(), registration);

[falken, 2014/11/19 04:19:56]

seems DCHECK_EQ is OK here

[xiang, 2014/11/24 07:04:00]

Done.

+  scoped_refptr<ServiceWorkerVersion> waiting_version =
+      registration->waiting_version();
+  CHECK_EQ(waiting_version->status(), ServiceWorkerVersion::INSTALLED);
+  waiting_version->RegisterStatusChangeCallback(
+      base::Bind(&ServiceWorkerProviderHost::SetControllerVersionAttribute,
+                 AsWeakPtr(), waiting_version));

[falken, 2014/11/19 04:19:56]

It's subtle that OnSkippedWaiting is called just before the skip to ACTIVE, so
it waits for any status change then sets controller. We won't detect an error if
the status change is to REDUNDANT for example.

Can ServiceWorkerRegistration instead call OnSkippepWaiting after setting the
version to ACTIVATING?

[xiang, 2014/11/24 07:04:00]

Yes, you are right, we can move it after ACTIVATING if only support current
registration replacing. Thanks!

+}
+
 void ServiceWorkerProviderHost::SetDocumentUrl(const GURL& url) {
   DCHECK(!url.has_ref());
   document_url_ = url;