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

cc/proto/layer.proto

 // 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.
 
 syntax = "proto2";
 
 import "display_item.proto";
 import "layer_position_constraint.proto";
 import "layer_sticky_position_constraint.proto";
 import "point3f.proto";
@@ skipping 26 matching lines @@
   };
 
   // required
   optional int32 id = 1;
   // required
   optional Type type = 2;
   optional int32 parent_id = 3;
   // A List of all the children of the current LayerNode.
   repeated LayerNode children = 4;
   optional LayerNode mask_layer = 5;
+
+  // Set for SolidColorScrollbarLayers.
+  optional SolidColorScrollbarLayerProperties solid_scrollbar = 7;
 }
 
 // A container for a list of dirty layers.
 message LayerUpdate {
   // A list of dirty layers.
   repeated LayerProperties layers = 1;
 }
 
 message LayerProperties {
   // required
   optional int32 id = 1;
 
   // The properties below are only read if |needs_push_properties| is set.
   // The Layer base class and each descendant have different proto messages
   // for their specific properties.
   optional BaseLayerProperties base = 5;
 
   // Only one of these fields may be set per LayerProperties.
   // TODO(dtrainor): use a 'oneof' union when it's supported in Chromium.  See
   // crbug.com/570371.
   optional PictureLayerProperties picture = 6;
-  optional SolidColorScrollbarLayerProperties solid_scrollbar = 7;
 }
 
 // NEXT ID: 59
 message BaseLayerProperties {
   // The following fields mirror the data stored in Layer::Inputs ----------
   optional Rect update_rect = 46;
   optional Size bounds = 3;
   optional bool masks_to_bounds = 14;
   optional float opacity = 22;
   optional SkXfermode.Mode blend_mode = 23;
@@ skipping 60 matching lines @@
   optional bool transform_is_invertible = 34;
   optional int32 num_descendants_that_draw_content = 36;
   repeated int32 scroll_children_ids = 41;
   repeated int32 clip_children_ids = 43;
 
   // TODO(nyquist): Figure out what to do with LayerAnimationController.
   // optional LayerAnimationController layer_animation_controller = ???;
 }
 
 message PictureLayerProperties {
+  // The following fields mirror the data stored in
+  // PictureLayer::PictureLayerInputs.------------------------

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

Style nit: do you really need -----, can we just separate blocks as

// This is blah.
one
two
three

four
five
six

is it clear that one two and three are blah but four five and six aren't?

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

I did it in the layer proto so did it here just to be consistent. Wouldn't worry
about this too much, its going to go away soon anyway.

+  optional bool nearest_neighbor = 5;
+  optional Rect recorded_viewport = 7;
+  optional DisplayItemList display_list = 8;
+  // --------------------------------------------------------
+
+  // TODO(khushalsagar): Remove these when crbug.com/648442
   optional RecordingSource recording_source = 1;
   optional Region invalidation = 2;
   optional Rect last_updated_visible_layer_rect = 3;
   optional bool is_mask = 4;
-  optional bool nearest_neighbor = 5;
-
   optional int64 update_source_frame_number = 6;
-
-  optional Rect recorded_viewport = 7;
-  optional DisplayItemList display_list = 8;
 }
 
 message SolidColorScrollbarLayerProperties {
   enum ScrollbarOrientation {
     HORIZONTAL = 0;
     VERTICAL = 1;
   };
 
   optional int32 scroll_layer_id = 1;
   optional int32 thumb_thickness = 2;
   optional int32 track_start = 3;
   optional bool is_left_side_vertical_scrollbar = 4;
   optional ScrollbarOrientation orientation = 5;
 }