cc: Use a ListContainer for DisplayItemList to reduce allocations.

cc/resources/compositing_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/compositing_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 "third_party/skia/include/core/SkPaint.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
 
-CompositingDisplayItem::CompositingDisplayItem(uint8_t alpha,
-                                               SkXfermode::Mode xfermode,
-                                               SkRect* bounds,
-                                               skia::RefPtr<SkColorFilter> cf)
-    : alpha_(alpha),
-      xfermode_(xfermode),
-      has_bounds_(!!bounds),
-      color_filter_(cf) {
-  if (bounds)
-    bounds_ = SkRect(*bounds);
+CompositingDisplayItem::CompositingDisplayItem() {
 }
 
 CompositingDisplayItem::~CompositingDisplayItem() {
 }
 
+void CompositingDisplayItem::SetNew(uint8_t alpha,
+                                    SkXfermode::Mode xfermode,
+                                    SkRect* bounds,
+                                    skia::RefPtr<SkColorFilter> cf) {
+  alpha_ = alpha;
+  xfermode_ = xfermode;
+  has_bounds_ = !!bounds;
+  if (bounds)
+    bounds_ = SkRect(*bounds);
+  color_filter_ = cf;
+}
+
 void CompositingDisplayItem::Raster(SkCanvas* canvas,
                                     SkDrawPictureCallback* callback) const {
   SkPaint paint;
   paint.setXfermodeMode(xfermode_);
   paint.setAlpha(alpha_);
   paint.setColorFilter(color_filter_.get());
   canvas->saveLayer(has_bounds_ ? &bounds_ : nullptr, &paint);
 }
 
 bool CompositingDisplayItem::IsSuitableForGpuRasterization() const {
@@ skipping 43 matching lines @@
 size_t EndCompositingDisplayItem::PictureMemoryUsage() const {
   return 0;
 }
 
 void EndCompositingDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString("EndCompositingDisplayItem");
 }
 
 }  // namespace cc