ui: Cleanup class/struct forward declarations

ui/ozone/platform/drm/gpu/screen_manager.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 UI_OZONE_PLATFORM_DRM_GPU_SCREEN_MANAGER_H_
 #define UI_OZONE_PLATFORM_DRM_GPU_SCREEN_MANAGER_H_
 
 #include <stdint.h>
 
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "base/observer_list.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/ozone/platform/drm/gpu/hardware_display_controller.h"
 
 typedef struct _drmModeModeInfo drmModeModeInfo;
 
 namespace gfx {
 class Point;
 class Rect;
-class Size;
 }  // namespace gfx
 
 namespace ui {
 
 class DrmDevice;
 class DrmWindow;
 class ScanoutBufferGenerator;
 
 // Responsible for keeping track of active displays and configuring them.
 class ScreenManager {
@@ skipping 99 matching lines @@
   HardwareDisplayControllers controllers_;
 
   WidgetToWindowMap window_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenManager);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRM_GPU_SCREEN_MANAGER_H_