Serialize PictureLayer properties.

cc/layers/empty_content_layer_client.h

+// 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.
+
+#ifndef CC_LAYERS_EMPTY_CONTENT_LAYER_CLIENT_H_
+#define CC_LAYERS_EMPTY_CONTENT_LAYER_CLIENT_H_
+
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "cc/base/cc_export.h"
+#include "cc/layers/content_layer_client.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace cc {
+
+class DisplayItemList;
+
+class CC_EXPORT EmptyContentLayerClient : public ContentLayerClient {

[vmpstr, 2015/12/18 07:42:33]

Can you add a class comment here to explain what this does / how it's used?

[David Trainor- moved to gerrit, 2016/01/04 06:50:15]

Done.

+ public:
+  static ContentLayerClient* GetInstance();
+
+  // ContentLayerClient implementation.
+  gfx::Rect PaintableRegion() override;
+  scoped_refptr<DisplayItemList> PaintContentsToDisplayList(
+      PaintingControlSetting painting_status) override;
+  bool FillsBoundsCompletely() const override;
+  size_t GetApproximateUnsharedMemoryUsage() const override;
+
+ private:
+  friend struct base::DefaultLazyInstanceTraits<EmptyContentLayerClient>;
+
+  EmptyContentLayerClient();
+  ~EmptyContentLayerClient() override;
+
+  DISALLOW_COPY_AND_ASSIGN(EmptyContentLayerClient);
+};
+
+}  // namespace cc
+
+#endif  // CC_LAYERS_EMPTY_CONTENT_LAYER_CLIENT_H_