Add support for (de)serializing LayerSelectionBound.

cc/input/layer_selection_bound.h

 // 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.
 
 #ifndef CC_INPUT_LAYER_SELECTION_BOUND_H_
 #define CC_INPUT_LAYER_SELECTION_BOUND_H_
 
 #include "cc/base/cc_export.h"
 #include "cc/input/selection.h"
 #include "cc/input/selection_bound_type.h"
 #include "ui/gfx/geometry/point.h"
 
 namespace cc {
 
+namespace proto {
+class LayerSelectionBound;
+}  // namespace proto
+
 // Marker for a selection end-point attached to a specific layer.
 struct CC_EXPORT LayerSelectionBound {
   LayerSelectionBound();
   ~LayerSelectionBound();
 
   SelectionBoundType type;
   gfx::Point edge_top;
   gfx::Point edge_bottom;
   int layer_id;
+
+  bool operator==(const LayerSelectionBound& other) const;
+  bool operator!=(const LayerSelectionBound& other) const;
+
+  void ToProtobuf(proto::LayerSelectionBound* proto) const;
+  void FromProtobuf(const proto::LayerSelectionBound& proto);
 };
 
-bool operator==(const LayerSelectionBound& lhs, const LayerSelectionBound& rhs);
-bool operator!=(const LayerSelectionBound& lhs, const LayerSelectionBound& rhs);
-
 typedef Selection<LayerSelectionBound> LayerSelection;
 
 }  // namespace cc
 
 #endif  // CC_INPUT_LAYER_SELECTION_BOUND_H_