Add support for (de)serializing cc::Layer properties.

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";
 
 package cc.proto;
 
 option optimize_for = LITE_RUNTIME;
 
@@ skipping 10 matching lines @@
   // required
   optional int32 id = 1;
   // required
   optional LayerType 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;
   optional LayerNode replica_layer = 6;
 }
+
+// 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;
+}
+
+message BaseLayerProperties {
+  // TODO(nyquist): Add all the required properties below. Huzzah!
+}