cc: Use a ListContainer for DisplayItemList to reduce allocations.

cc/resources/clip_display_item.h

Index: cc/resources/clip_display_item.h
diff --git a/cc/resources/clip_display_item.h b/cc/resources/clip_display_item.h
index e5e72bffbfb9ca76ba144b6f3fed5b22f5e99b9c..8882411f4bf5037101b1223b305687bb425adef8 100644
--- a/cc/resources/clip_display_item.h
+++ b/cc/resources/clip_display_item.h
@@ -20,13 +20,11 @@ namespace cc {
 
 class CC_EXPORT ClipDisplayItem : public DisplayItem {
  public:
+  ClipDisplayItem();
   ~ClipDisplayItem() override;
 
-  static scoped_ptr<ClipDisplayItem> Create(
-      gfx::Rect clip_rect,
-      const std::vector<SkRRect>& rounded_clip_rects) {
-    return make_scoped_ptr(new ClipDisplayItem(clip_rect, rounded_clip_rects));
-  }
+  void SetNew(gfx::Rect clip_rect,
+              const std::vector<SkRRect>& rounded_clip_rects);
 
   void Raster(SkCanvas* canvas, SkDrawPictureCallback* callback) const override;
 
@@ -46,21 +44,15 @@ class CC_EXPORT ClipDisplayItem : public DisplayItem {
 
 class CC_EXPORT EndClipDisplayItem : public DisplayItem {
  public:
+  EndClipDisplayItem();
   ~EndClipDisplayItem() override;
 
-  static scoped_ptr<EndClipDisplayItem> Create() {
-    return make_scoped_ptr(new EndClipDisplayItem());
-  }
-
   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:
-  EndClipDisplayItem();
 };
 
 }  // namespace cc