cc/blimp: Add (de)-serialization for PictureLayer and ScrollbarLayer.

cc/layers/picture_layer.h

 // Copyright 2012 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_PICTURE_LAYER_H_
 #define CC_LAYERS_PICTURE_LAYER_H_
 
 #include "base/macros.h"
 #include "cc/base/invalidation_region.h"
 #include "cc/debug/devtools_instrumentation.h"
@@ skipping 50 matching lines @@
     bool nearest_neighbor = false;
     gfx::Rect recorded_viewport;
     scoped_refptr<DisplayItemList> display_list;
     size_t painter_reported_memory_usage = 0;
   };
 
   explicit PictureLayer(ContentLayerClient* client);
   // Allow tests to inject a recording source.
   PictureLayer(ContentLayerClient* client,
                std::unique_ptr<RecordingSource> source);
+  PictureLayer(int engine_layer_id, ContentLayerClient* client);

[vmpstr, 2016/10/07 23:50:05]

This is... weird. Should this be "layer_id". I kind of don't like adding ctors
that are only used in tests. We usually use either ForTesting or overload for
this type of thing.

[Khushal, 2016/10/08 00:41:33]

Not needed anymore. Removed.

   ~PictureLayer() override;
 
   bool HasDrawableContent() const override;
   void SetTypeForProtoSerialization(proto::LayerNode* proto) const override;
   void LayerSpecificPropertiesToProto(proto::LayerProperties* proto,
                                       bool inputs_only) override;
   void FromLayerSpecificPropertiesProto(
       const proto::LayerProperties& proto) override;
 
   bool is_mask() const { return is_mask_; }
@@ skipping 13 matching lines @@
 
   int update_source_frame_number_;
   bool is_mask_;
 
   DISALLOW_COPY_AND_ASSIGN(PictureLayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_H_