content: Cleanup class/struct forward declarations

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 <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "content/browser/service_worker/service_worker_version.h"
 #include "content/common/content_export.h"
 #include "content/common/service_worker/service_worker_types.h"
 
-namespace IPC {
-class Sender;
-}
-
 namespace content {
 
 class ServiceWorkerContextCore;
 
 // Roughly corresponds to one WebServiceWorker object in the renderer process.
 //
 // The renderer process maintains the reference count by owning a
 // ServiceWorkerHandleReference for each reference it has to the service worker
 // object. ServiceWorkerHandleReference creation and destruction sends an IPC to
 // the browser process, which adjusts the ServiceWorkerHandle refcount.
@@ skipping 36 matching lines @@
   const int handle_id_;
   int ref_count_;  // Created with 1.
   scoped_refptr<ServiceWorkerVersion> version_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerHandle);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_HANDLE_H_