Serialize PictureLayer properties.

cc/playback/display_list_recording_source.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/playback/display_list_recording_source.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 
@@ skipping 43 matching lines @@
   SizeToProto(size_, proto->mutable_size());
   proto->set_slow_down_raster_scale_factor_for_debug(
       slow_down_raster_scale_factor_for_debug_);
   proto->set_generate_discardable_images_metadata(
       generate_discardable_images_metadata_);
   proto->set_requires_clear(requires_clear_);
   proto->set_is_solid_color(is_solid_color_);
   proto->set_clear_canvas_with_debug_color(clear_canvas_with_debug_color_);
   proto->set_solid_color(static_cast<uint64_t>(solid_color_));
   proto->set_background_color(static_cast<uint64_t>(background_color_));
-  display_list_->ToProtobuf(proto->mutable_display_list());
+  if (display_list_)
+    display_list_->ToProtobuf(proto->mutable_display_list());
 }
 
 void DisplayListRecordingSource::FromProtobuf(
     const proto::DisplayListRecordingSource& proto) {
   recorded_viewport_ = ProtoToRect(proto.recorded_viewport());
   size_ = ProtoToSize(proto.size());
   slow_down_raster_scale_factor_for_debug_ =
       proto.slow_down_raster_scale_factor_for_debug();
   generate_discardable_images_metadata_ =
       proto.generate_discardable_images_metadata();
   requires_clear_ = proto.requires_clear();
   is_solid_color_ = proto.is_solid_color();
   clear_canvas_with_debug_color_ = proto.clear_canvas_with_debug_color();
   solid_color_ = static_cast<SkColor>(proto.solid_color());
   background_color_ = static_cast<SkColor>(proto.background_color());
-  display_list_ = DisplayItemList::CreateFromProto(proto.display_list());
 
-  FinishDisplayItemListUpdate();
+  // This might not exist if the |display_list_| of the serialized
+  // DisplayListRecordingSource was null, wich can happen if |Clear()| is
+  // called.
+  if (proto.has_display_list()) {
+    display_list_ = DisplayItemList::CreateFromProto(proto.display_list());
+    FinishDisplayItemListUpdate();
+  } else {
+    display_list_ = nullptr;
+  }
 }
 
 void DisplayListRecordingSource::UpdateInvalidationForNewViewport(
     const gfx::Rect& old_recorded_viewport,
     const gfx::Rect& new_recorded_viewport,
     Region* invalidation) {
   // Invalidate newly-exposed and no-longer-exposed areas.
   Region newly_exposed_region(new_recorded_viewport);
   newly_exposed_region.Subtract(old_recorded_viewport);
   invalidation->Union(newly_exposed_region);
@@ skipping 130 matching lines @@
 }
 
 void DisplayListRecordingSource::Clear() {
   recorded_viewport_ = gfx::Rect();
   display_list_ = nullptr;
   painter_reported_memory_usage_ = 0;
   is_solid_color_ = false;
 }
 
 }  // namespace cc