cc: Use a ListContainer for DisplayItemList to reduce allocations.

cc/resources/transform_display_item.cc

 // 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.
 
 #include "cc/resources/transform_display_item.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 
 namespace cc {
 
-TransformDisplayItem::TransformDisplayItem(const gfx::Transform& transform)
-    : transform_(transform) {
+TransformDisplayItem::TransformDisplayItem()
+    : transform_(gfx::Transform::kSkipInitialization) {
 }
 
 TransformDisplayItem::~TransformDisplayItem() {
 }
 
+void TransformDisplayItem::SetNew(const gfx::Transform& transform) {
+  transform_ = transform;
+}
+
 void TransformDisplayItem::Raster(SkCanvas* canvas,
                                   SkDrawPictureCallback* callback) const {
   canvas->save();
   if (!transform_.IsIdentity())
     canvas->concat(transform_.matrix());
 }
 
 bool TransformDisplayItem::IsSuitableForGpuRasterization() const {
   return true;
 }
@@ skipping 34 matching lines @@
 size_t EndTransformDisplayItem::PictureMemoryUsage() const {
   return 0;
 }
 
 void EndTransformDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString("EndTransformDisplayItem");
 }
 
 }  // namespace cc