service worker: Observe when resource context is shutting down

content/browser/service_worker/service_worker_context_wrapper.cc

Index: content/browser/service_worker/service_worker_context_wrapper.cc
diff --git a/content/browser/service_worker/service_worker_context_wrapper.cc b/content/browser/service_worker/service_worker_context_wrapper.cc
index 85d9830a529c493123c99ac40774c86816ed4696..1dafcef098b02b8f0fef19f5a4fd82da70792057 100644
--- a/content/browser/service_worker/service_worker_context_wrapper.cc
+++ b/content/browser/service_worker/service_worker_context_wrapper.cc
@@ -130,6 +130,29 @@ void ServiceWorkerContextWrapper::Shutdown() {
       base::Bind(&ServiceWorkerContextWrapper::ShutdownOnIO, this));
 }
 
+void ServiceWorkerContextWrapper::InitializeResourceContext(
+    ResourceContext* resource_context,
+    scoped_refptr<net::URLRequestContextGetter> request_context_getter) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  resource_context_ = resource_context;
+  request_context_getter_ = request_context_getter;
+  // Can be null in tests.
+  if (request_context_getter_)
+    request_context_getter_->AddObserver(this);
+}
+
+void ServiceWorkerContextWrapper::OnContextShuttingDown() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  request_context_getter_->RemoveObserver(this);

[michaeln, 2016/03/10 21:15:53]

You mentioned this isn't called on ContentShell.

I think it might be good to RemoveObserver() in ShutdownOnIO() and to assert
that resource_context_ is null in the dtor? So we don't depend on
ResourcedContextShutdown happening prior to ServiceWorkerContextWrapper
destruction.

[mmenke, 2016/03/10 21:20:51]

I view this as a hack to resolve incorrect class dependencies.  I'm reluctant to
encourage increasing the amount of code that relies on it.

+
+  // OnContextShuttingDown is called when the ProfileIOData (ResourceContext) is
+  // shutting down, so call ShutdownOnIO() to clear resource_context_.
+  // This doesn't seem to be called when using content_shell, so we still must
+  // also call ShutdownOnIO() in Shutdown(), which is called when the storage
+  // partition is destroyed.
+  ShutdownOnIO();
+}
+
 void ServiceWorkerContextWrapper::DeleteAndStartOver() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (!context_core_) {
@@ -158,12 +181,6 @@ ResourceContext* ServiceWorkerContextWrapper::resource_context() {
   return resource_context_;
 }
 
-void ServiceWorkerContextWrapper::set_resource_context(
-    ResourceContext* resource_context) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  resource_context_ = resource_context;
-}
-
 static void FinishRegistrationOnIO(
     const ServiceWorkerContext::ResultCallback& continuation,
     ServiceWorkerStatusCode status,