Update from https://crrev.com/318214

cc/resources/transparency_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/transparency_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 {
-
-TransparencyDisplayItem::TransparencyDisplayItem(float opacity,
-                                                 SkXfermode::Mode blend_mode)
-    : opacity_(opacity), blend_mode_(blend_mode) {
-}
-
-TransparencyDisplayItem::~TransparencyDisplayItem() {
-}
-
-void TransparencyDisplayItem::Raster(SkCanvas* canvas,
-                                     SkDrawPictureCallback* callback) const {
-  SkPaint paint;
-  paint.setXfermodeMode(blend_mode_);
-  paint.setAlpha(opacity_ * 255);
-  canvas->saveLayer(NULL, &paint);
-}
-
-bool TransparencyDisplayItem::IsSuitableForGpuRasterization() const {
-  return true;
-}
-
-int TransparencyDisplayItem::ApproximateOpCount() const {
-  return 1;
-}
-
-size_t TransparencyDisplayItem::PictureMemoryUsage() const {
-  return sizeof(float) + sizeof(SkXfermode::Mode);
-}
-
-void TransparencyDisplayItem::AsValueInto(
-    base::trace_event::TracedValue* array) const {
-  array->AppendString(
-      base::StringPrintf("TransparencyDisplayItem opacity: %f, blend_mode: %d",
-                         opacity_, blend_mode_));
-}
-
-EndTransparencyDisplayItem::EndTransparencyDisplayItem() {
-}
-
-EndTransparencyDisplayItem::~EndTransparencyDisplayItem() {
-}
-
-void EndTransparencyDisplayItem::Raster(SkCanvas* canvas,
-                                        SkDrawPictureCallback* callback) const {
-  canvas->restore();
-}
-
-bool EndTransparencyDisplayItem::IsSuitableForGpuRasterization() const {
-  return true;
-}
-
-int EndTransparencyDisplayItem::ApproximateOpCount() const {
-  return 0;
-}
-
-size_t EndTransparencyDisplayItem::PictureMemoryUsage() const {
-  return 0;
-}
-
-void EndTransparencyDisplayItem::AsValueInto(
-    base::trace_event::TracedValue* array) const {
-  array->AppendString("EndTransparencyDisplayItem");
-}
-
-}  // namespace cc