Cleanup: Remove unneeded forward declarations in views.

views/controls/menu/native_menu_host_delegate.h

 // Copyright (c) 2011 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 VIEWS_CONTROLS_MENU_NATIVE_MENU_HOST_DELEGATE_H_
 #define VIEWS_CONTROLS_MENU_NATIVE_MENU_HOST_DELEGATE_H_
 
 namespace views {
+
 class MenuHost;
-class RootView;
+
 namespace internal {
+
 class NativeWidgetDelegate;
 
 class NativeMenuHostDelegate {
  public:
   virtual ~NativeMenuHostDelegate() {}
 
   // Called when the NativeMenuHost is being destroyed.
   virtual void OnNativeMenuHostDestroy() = 0;
 
   // Called when the NativeMenuHost is losing input capture.
   virtual void OnNativeMenuHostCancelCapture() = 0;
 
   virtual NativeWidgetDelegate* AsNativeWidgetDelegate() = 0;
 };
 
 }  // namespace internal
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_MENU_NATIVE_MENU_HOST_DELEGATE_H_
-