Update from https://crrev.com/306655

cc/resources/display_item_list.h

+// 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.
+
+#ifndef CC_RESOURCES_DISPLAY_ITEM_LIST_H_
+#define CC_RESOURCES_DISPLAY_ITEM_LIST_H_
+
+#include "base/debug/trace_event.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "cc/base/cc_export.h"
+#include "cc/base/scoped_ptr_vector.h"
+#include "cc/resources/display_item.h"
+#include "ui/gfx/rect.h"
+
+class SkCanvas;
+class SkDrawPictureCallback;
+
+namespace cc {
+
+class CC_EXPORT DisplayItemList
+    : public base::RefCountedThreadSafe<DisplayItemList> {
+ public:
+  static scoped_refptr<DisplayItemList> Create();
+
+  void Raster(SkCanvas* canvas,
+              SkDrawPictureCallback* callback,
+              float contents_scale) const;
+
+  void AppendItem(scoped_ptr<DisplayItem> item);
+
+  bool IsSuitableForGpuRasterization() const;
+  int ApproximateOpCount() const;
+  size_t PictureMemoryUsage() const;
+
+  scoped_refptr<base::debug::ConvertableToTraceFormat> AsValue() const;
+
+  void EmitTraceSnapshot() const;
+
+ private:
+  DisplayItemList();
+  ~DisplayItemList();
+  ScopedPtrVector<DisplayItem> items_;
+  bool is_suitable_for_gpu_rasterization_;
+  int approximate_op_count_;
+
+  friend class base::RefCountedThreadSafe<DisplayItemList>;
+  DISALLOW_COPY_AND_ASSIGN(DisplayItemList);
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_DISPLAY_ITEM_LIST_H_