chrome: Cleanup class/struct forward declarations

chrome/browser/devtools/devtools_window.h

 // Copyright (c) 2012 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 CHROME_BROWSER_DEVTOOLS_DEVTOOLS_WINDOW_H_
 #define CHROME_BROWSER_DEVTOOLS_DEVTOOLS_WINDOW_H_
 
 #include "base/macros.h"
 #include "chrome/browser/devtools/devtools_contents_resizing_strategy.h"
 #include "chrome/browser/devtools/devtools_toggle_action.h"
 #include "chrome/browser/devtools/devtools_ui_bindings.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/browser/web_contents_observer.h"
 
 class Browser;
 class BrowserWindow;
 class DevToolsWindowTesting;
 class DevToolsEventForwarder;
 
 namespace content {
 class DevToolsAgentHost;
 struct NativeWebKeyboardEvent;
 class RenderFrameHost;
-class RenderViewHost;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 class DevToolsWindow : public DevToolsUIBindings::Delegate,
                        public content::WebContentsDelegate {
  public:
   class ObserverWithAccessor : public content::WebContentsObserver {
@@ skipping 321 matching lines @@
   base::Closure ready_for_test_callback_;
 
   base::TimeTicks inspect_element_start_time_;
   std::unique_ptr<DevToolsEventForwarder> event_forwarder_;
 
   friend class DevToolsEventForwarder;
   DISALLOW_COPY_AND_ASSIGN(DevToolsWindow);
 };
 
 #endif  // CHROME_BROWSER_DEVTOOLS_DEVTOOLS_WINDOW_H_