content: Cleanup class/struct forward declarations

content/browser/renderer_host/render_widget_host_view_mac.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 CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 #include <IOSurface/IOSurface.h>
 #include <stddef.h>
@@ skipping 30 matching lines @@
 
 namespace content {
 class RenderWidgetHost;
 class RenderWidgetHostImpl;
 class RenderWidgetHostViewMac;
 class RenderWidgetHostViewMacEditCommandHelper;
 class WebContents;
 struct TextInputState;
 }
 
-namespace ui {
-class Compositor;
-class Layer;
-}
-
 @class FullscreenWindowManager;
 @protocol RenderWidgetHostViewMacDelegate;
 
 @protocol RenderWidgetHostViewMacOwner
 - (content::RenderWidgetHostViewMac*)renderWidgetHostViewMac;
 @end
 
 // This is the view that lives in the Cocoa view hierarchy. In Windows-land,
 // RenderWidgetHostViewWin is both the view and the delegate. We split the roles
 // but that means that the view needs to own the delegate and will dispose of it
@@ skipping 491 matching lines @@
 
   // Factory used to safely scope delayed calls to ShutdownHost().
   base::WeakPtrFactory<RenderWidgetHostViewMac> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_