Introduce ServiceWorkerHandle for tracking WebServiceWorkerImpl reference

content/browser/service_worker/service_worker_version.h

Index: content/browser/service_worker/service_worker_version.h
diff --git a/content/browser/service_worker/service_worker_version.h b/content/browser/service_worker/service_worker_version.h
index e362e1615f7545300043f678440f6e41de39ae49..668a9aac12160d8b2cf5eba6f4c8612354ab9e1b 100644
--- a/content/browser/service_worker/service_worker_version.h
+++ b/content/browser/service_worker/service_worker_version.h
@@ -68,16 +68,18 @@ class CONTENT_EXPORT ServiceWorkerVersion
                  // different states for different termination sequences)
   };
 
+  class Listener {
+   public:
+    virtual void OnVersionStateChanged() = 0;
+  };
+
   ServiceWorkerVersion(
       ServiceWorkerRegistration* registration,
       int64 version_id,
       base::WeakPtr<ServiceWorkerContextCore> context);
 
   int64 version_id() const { return version_id_; }
-  ServiceWorkerRegistration* registration() { return registration_.get(); }
-
-  void Shutdown();
-  bool is_shutdown() const { return is_shutdown_; }
+  int64 registration_id() const { return registration_id_; }
 
   RunningStatus running_status() const {
     return static_cast<RunningStatus>(embedded_worker_->status());
@@ -186,9 +188,9 @@ class CONTENT_EXPORT ServiceWorkerVersion
   virtual ~ServiceWorkerVersion();
 
   const int64 version_id_;
+  int64 registration_id_;
+  GURL script_url_;
   Status status_;
-  bool is_shutdown_;
-  scoped_refptr<ServiceWorkerRegistration> registration_;
   scoped_ptr<EmbeddedWorkerInstance> embedded_worker_;
   std::vector<StatusCallback> start_callbacks_;
   std::vector<StatusCallback> stop_callbacks_;