ui: Cleanup class/struct forward declarations

ui/android/delegated_frame_host_android.h

 // Copyright 2016 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 UI_ANDROID_DELEGATED_FRAME_HOST_ANDROID_H_
 #define UI_ANDROID_DELEGATED_FRAME_HOST_ANDROID_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/resources/returned_resource.h"
 #include "cc/surfaces/surface_factory.h"
 #include "cc/surfaces/surface_factory_client.h"
 #include "ui/android/ui_android_export.h"
 #include "ui/gfx/selection_bound.h"
 
 namespace cc {
 
 class CompositorFrame;
-class CopyOutputResult;
 class Layer;
-class SurfaceId;
 class SurfaceManager;
 class SurfaceLayer;
 class SurfaceIdAllocator;
 enum class SurfaceDrawStatus;
 
 }  // namespace cc
 
 namespace ui {
 class ViewAndroid;
 class WindowAndroidCompositor;
@@ skipping 74 matching lines @@
   scoped_refptr<cc::Layer> background_layer_;
 
   gfx::Size container_size_in_dip_;
 
   DISALLOW_COPY_AND_ASSIGN(DelegatedFrameHostAndroid);
 };
 
 }  // namespace ui
 
 #endif  // UI_ANDROID_DELEGATED_FRAME_HOST_ANDROID_H_