cc: Use a ListContainer for DisplayItemList to reduce allocations.

cc/resources/float_clip_display_item.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 CC_RESOURCES_FLOAT_CLIP_DISPLAY_ITEM_H_
 #define CC_RESOURCES_FLOAT_CLIP_DISPLAY_ITEM_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
 #include "cc/resources/display_item.h"
 #include "ui/gfx/geometry/rect_f.h"
 
 class SkCanvas;
 class SkDrawPictureCallback;
 
 namespace cc {
 
 class CC_EXPORT FloatClipDisplayItem : public DisplayItem {
  public:
+  FloatClipDisplayItem();
   ~FloatClipDisplayItem() override;
 
-  static scoped_ptr<FloatClipDisplayItem> Create(gfx::RectF clip_rect) {
-    return make_scoped_ptr(new FloatClipDisplayItem(clip_rect));
-  }
+  void SetNew(const gfx::RectF& clip_rect);
 
   void Raster(SkCanvas* canvas, SkDrawPictureCallback* callback) const override;
 
   bool IsSuitableForGpuRasterization() const override;
   int ApproximateOpCount() const override;
   size_t PictureMemoryUsage() const override;
   void AsValueInto(base::trace_event::TracedValue* array) const override;
 
  protected:
   explicit FloatClipDisplayItem(gfx::RectF clip_rect);
 
  private:
   gfx::RectF clip_rect_;
 };
 
 class CC_EXPORT EndFloatClipDisplayItem : public DisplayItem {
  public:
+  EndFloatClipDisplayItem();
   ~EndFloatClipDisplayItem() override;
 
   static scoped_ptr<EndFloatClipDisplayItem> Create() {
     return make_scoped_ptr(new EndFloatClipDisplayItem());
   }
 
   void Raster(SkCanvas* canvas, SkDrawPictureCallback* callback) const override;
 
   bool IsSuitableForGpuRasterization() const override;
   int ApproximateOpCount() const override;
   size_t PictureMemoryUsage() const override;
   void AsValueInto(base::trace_event::TracedValue* array) const override;
-
- protected:
-  EndFloatClipDisplayItem();
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_FLOAT_CLIP_DISPLAY_ITEM_H_