Introduce ServiceWorkerHandle for tracking WebServiceWorkerImpl reference

content/browser/service_worker/service_worker_handle.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_HANDLE_H_
+#define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_HANDLE_H_
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "content/browser/service_worker/service_worker_version.h"
+
+namespace IPC {
+class Sender;
+}
+
+namespace content {
+
+class ServiceWorkerContextCore;
+class ServiceWorkerRegistration;
+
+// Roughly corresponds to one ServiceWorker object in the renderer process
+// (WebServiceWorkerImpl).
+// Has references to the corresponding ServiceWorkerVersion and
+// ServiceWorkerRegistration (therefore they're guaranteed to be alive while
+// this handle is around).
+class ServiceWorkerHandle : public ServiceWorkerVersion::Listener {
+ public:
+  // Creates a handle for a live version. The version's corresponding
+  // registration must be also alive.
+  // This may return NULL if |context|.get() or |version| is NULL.
+  static scoped_ptr<ServiceWorkerHandle> Create(
+      base::WeakPtr<ServiceWorkerContextCore> context,
+      IPC::Sender* sender,
+      ServiceWorkerVersion* version);
+
+  ServiceWorkerHandle(base::WeakPtr<ServiceWorkerContextCore> context,
+                      IPC::Sender* sender,
+                      ServiceWorkerRegistration* registration,
+                      ServiceWorkerVersion* version);
+  ~ServiceWorkerHandle();
+
+  // ServiceWorkerVersion::Listener overrides.
+  virtual void OnVersionStateChanged() OVERRIDE;
+
+  ServiceWorkerRegistration* registration() { return registration_.get(); }
+  ServiceWorkerVersion* version() { return version_.get(); }
+
+ private:
+  base::WeakPtr<ServiceWorkerContextCore> context_;
+  IPC::Sender* sender_;  // Not owned, it should always outlive this.
+  scoped_refptr<ServiceWorkerRegistration> registration_;
+  scoped_refptr<ServiceWorkerVersion> version_;
+
+  DISALLOW_COPY_AND_ASSIGN(ServiceWorkerHandle);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_HANDLE_H_