Serialize DisplayListRecordingSource to protos.

cc/playback/display_list_recording_source.h

Index: cc/playback/display_list_recording_source.h
diff --git a/cc/playback/display_list_recording_source.h b/cc/playback/display_list_recording_source.h
index 603924f070c45a97ccbebc6a37b0ef9fd699aeb0..eac32a14f416b278d78a2541b72532ad7eed0000 100644
--- a/cc/playback/display_list_recording_source.h
+++ b/cc/playback/display_list_recording_source.h
@@ -13,6 +13,11 @@
 #include "ui/gfx/geometry/size.h"
 
 namespace cc {
+
+namespace proto {
+class DisplayListRecordingSource;
+}
+
 class ContentLayerClient;
 class DisplayItemList;
 class DisplayListRasterSource;
@@ -34,6 +39,9 @@ class CC_EXPORT DisplayListRecordingSource {
   DisplayListRecordingSource();
   virtual ~DisplayListRecordingSource();
 
+  void ToProtobuf(proto::DisplayListRecordingSource* proto) const;
+  void FromProtobuf(const proto::DisplayListRecordingSource& proto);
+
   bool UpdateAndExpandInvalidation(ContentLayerClient* painter,
                                    Region* invalidation,
                                    const gfx::Size& layer_size,