ui: Cleanup class/struct forward declarations

ui/compositor/paint_recorder.h

 // Copyright 2015 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_COMPOSITOR_PAINT_RECORDER_H_
 #define UI_COMPOSITOR_PAINT_RECORDER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "ui/compositor/compositor_export.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/rect.h"
 
-namespace cc {
-class DisplayItemList;
-}
-
 namespace gfx {
 class Canvas;
 }
 
-class SkCanvas;
-class SkPictureRecorder;
-
 namespace ui {
 class PaintCache;
 class PaintContext;
 
 // A class to hide the complexity behind setting up a recording into a
 // DisplayItem. This is meant to be short-lived within the scope of recording
 // taking place, the DisplayItem should be removed from the PaintRecorder once
 // recording is complete and can be cached.
 class COMPOSITOR_EXPORT PaintRecorder {
  public:
@@ skipping 13 matching lines @@
   gfx::Canvas canvas_;
   PaintCache* cache_;
   gfx::Rect bounds_in_layer_;
 
   DISALLOW_COPY_AND_ASSIGN(PaintRecorder);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_PAINT_RECORDER_H_