cc: Use a ListContainer for DisplayItemList to reduce allocations.

cc/resources/float_clip_display_item.cc

 // 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.
 
 #include "cc/resources/float_clip_display_item.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
 
-FloatClipDisplayItem::FloatClipDisplayItem(gfx::RectF clip_rect)
-    : clip_rect_(clip_rect) {
+FloatClipDisplayItem::FloatClipDisplayItem() {
 }
 
 FloatClipDisplayItem::~FloatClipDisplayItem() {
 }
 
+void FloatClipDisplayItem::SetNew(const gfx::RectF& clip_rect) {
+  clip_rect_ = clip_rect;
+}
+
 void FloatClipDisplayItem::Raster(SkCanvas* canvas,
                                   SkDrawPictureCallback* callback) const {
   canvas->save();
   canvas->clipRect(gfx::RectFToSkRect(clip_rect_));
 }
 
 bool FloatClipDisplayItem::IsSuitableForGpuRasterization() const {
   return true;
 }
 
@@ skipping 33 matching lines @@
 size_t EndFloatClipDisplayItem::PictureMemoryUsage() const {
   return 0;
 }
 
 void EndFloatClipDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString("EndFloatClipDisplayItem");
 }
 
 }  // namespace cc