ServiceWorker: Confirm the liveness of the associated context before handling message

content/browser/service_worker/service_worker_context_wrapper.h

Index: content/browser/service_worker/service_worker_context_wrapper.h
diff --git a/content/browser/service_worker/service_worker_context_wrapper.h b/content/browser/service_worker/service_worker_context_wrapper.h
index 029af6f54ca417f37470d62762e3716551e1affe..20899c5001d7a3a380aa3d9c9e2fa81e7a578f21 100644
--- a/content/browser/service_worker/service_worker_context_wrapper.h
+++ b/content/browser/service_worker/service_worker_context_wrapper.h
@@ -29,6 +29,7 @@ namespace content {
 class BrowserContext;
 class ServiceWorkerContextCore;
 class ServiceWorkerContextObserver;
+class ServiceWorkerProviderHostRegistry;
 
 // A refcounted wrapper class for our core object. Higher level content lib
 // classes keep references to this class on mutliple threads. The inner core
@@ -54,6 +55,10 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
     return process_manager_.get();
   }
 
+  ServiceWorkerProviderHostRegistry* provider_registry() {
+    return provider_registry_.get();
+  }
+
   // ServiceWorkerContext implementation:
   virtual void RegisterServiceWorker(
       const GURL& pattern,
@@ -84,6 +89,8 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
   const scoped_ptr<ServiceWorkerProcessManager> process_manager_;
   // Cleared in Shutdown():
   scoped_ptr<ServiceWorkerContextCore> context_core_;
+
+  scoped_ptr<ServiceWorkerProviderHostRegistry> provider_registry_;
 };
 
 }  // namespace content