cc : Make tree synchronization independent of layer tree hierarchy (2)

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_list_recording_source.proto";
 import "layer_position_constraint.proto";
 import "point3f.proto";
 import "pointf.proto";
@@ skipping 35 matching lines @@
 
 // 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;
-  // required
-  optional bool needs_push_properties = 3;
-  // required
-  optional int32 num_dependents_need_push_properties = 4;
 
   // 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;
@@ skipping 65 matching lines @@
 
 message PictureLayerProperties {
   optional DisplayListRecordingSource 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;
 }