Add protobuf serialization to DisplayItemList

cc/playback/filter_display_item.cc

Index: cc/playback/filter_display_item.cc
diff --git a/cc/playback/filter_display_item.cc b/cc/playback/filter_display_item.cc
index 48fcab33ec10f4b7ccba9e30b16dd4d0e03badeb..df9b0063b2ce94ab60d7b285cd1b2b3d6b0523bf 100644
--- a/cc/playback/filter_display_item.cc
+++ b/cc/playback/filter_display_item.cc
@@ -7,6 +7,8 @@
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/output/render_surface_filters.h"
+#include "cc/proto/display_item.pb.h"
+#include "cc/proto/gfx_conversions.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkImageFilter.h"
@@ -34,6 +36,27 @@ void FilterDisplayItem::SetNew(const FilterOperations& filters,
                       external_memory_usage);
 }
 
+void FilterDisplayItem::ToProtobuf(proto::DisplayItem* proto) {
+  proto->set_type(proto::DisplayItem::Type_Filter);
+
+  proto::FilterDisplayItem* details = proto->mutable_details_filter();
+  RectFToProto(bounds_, details->mutable_bounds());
+
+  // TODO(dtrainor): Support serializing FilterOperations.
+}
+
+void FilterDisplayItem::FromProtobuf(const proto::DisplayItem& proto) {
+  DCHECK_EQ(proto::DisplayItem::Type_Filter, proto.type());
+
+  const proto::FilterDisplayItem& details = proto.details_filter();
+  gfx::RectF bounds = ProtoToRectF(details.bounds());
+
+  // TODO(dtrainor): Support deserializing FilterOperations.
+  FilterOperations filters;
+
+  SetNew(filters, bounds);
+}
+
 void FilterDisplayItem::Raster(SkCanvas* canvas,
                                const gfx::Rect& canvas_target_playback_rect,
                                SkPicture::AbortCallback* callback) const {
@@ -80,6 +103,14 @@ EndFilterDisplayItem::EndFilterDisplayItem() {
 EndFilterDisplayItem::~EndFilterDisplayItem() {
 }
 
+void EndFilterDisplayItem::ToProtobuf(proto::DisplayItem* proto) {
+  proto->set_type(proto::DisplayItem::Type_EndFilter);
+}
+
+void EndFilterDisplayItem::FromProtobuf(const proto::DisplayItem& proto) {
+  DCHECK_EQ(proto::DisplayItem::Type_EndFilter, proto.type());
+}
+
 void EndFilterDisplayItem::Raster(SkCanvas* canvas,
                                   const gfx::Rect& canvas_target_playback_rect,
                                   SkPicture::AbortCallback* callback) const {