Add protobuf serialization to DisplayItemList

cc/playback/clip_display_item.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 CC_PLAYBACK_CLIP_DISPLAY_ITEM_H_
 #define CC_PLAYBACK_CLIP_DISPLAY_ITEM_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
 #include "cc/playback/display_item.h"
 #include "third_party/skia/include/core/SkRRect.h"
 #include "ui/gfx/geometry/rect.h"
 
 class SkCanvas;
 
 namespace cc {
 
 class CC_EXPORT ClipDisplayItem : public DisplayItem {
  public:
   ClipDisplayItem();
   ~ClipDisplayItem() override;
 
   void SetNew(gfx::Rect clip_rect,
               const std::vector<SkRRect>& rounded_clip_rects);
 
+  void ToProtobuf(proto::DisplayItem* proto) override;
+  void FromProtobuf(const proto::DisplayItem& proto) override;
   void Raster(SkCanvas* canvas,
               const gfx::Rect& canvas_target_playback_rect,
               SkPicture::AbortCallback* callback) const override;
   void AsValueInto(base::trace_event::TracedValue* array) const override;
   void ProcessForBounds(
       DisplayItemListBoundsCalculator* calculator) const override;
 
  private:
   gfx::Rect clip_rect_;
   std::vector<SkRRect> rounded_clip_rects_;
 };
 
 class CC_EXPORT EndClipDisplayItem : public DisplayItem {
  public:
   EndClipDisplayItem();
   ~EndClipDisplayItem() override;
 
+  void ToProtobuf(proto::DisplayItem* proto) override;
+  void FromProtobuf(const proto::DisplayItem& proto) override;
   void Raster(SkCanvas* canvas,
               const gfx::Rect& canvas_target_playback_rect,
               SkPicture::AbortCallback* callback) const override;
   void AsValueInto(base::trace_event::TracedValue* array) const override;
   void ProcessForBounds(
       DisplayItemListBoundsCalculator* calculator) const override;
 };
 
 }  // namespace cc
 
 #endif  // CC_PLAYBACK_CLIP_DISPLAY_ITEM_H_