Add support for converting cc::Region to and from protobuf.

cc/base/region.h

 // Copyright (c) 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_BASE_REGION_H_
 #define CC_BASE_REGION_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/skia_util.h"
 
 namespace base {
 class Value;
 namespace trace_event {
 class TracedValue;
 }
 }
 
 namespace cc {
 class SimpleEnclosedRegion;
 
+namespace proto {
+class Region;
+}  // namespace proto
+
 class CC_EXPORT Region {
  public:
   Region();
   Region(const Region& region);
   Region(const gfx::Rect& rect);  // NOLINT(runtime/explicit)
   ~Region();
 
   const Region& operator=(const gfx::Rect& rect);
   const Region& operator=(const Region& region);
 
@@ skipping 22 matching lines @@
   }
 
   gfx::Rect bounds() const {
     return gfx::SkIRectToRect(skregion_.getBounds());
   }
 
   std::string ToString() const;
   scoped_ptr<base::Value> AsValue() const;
   void AsValueInto(base::trace_event::TracedValue* array) const;
 
+  void ToProtobuf(proto::Region* proto) const;
+  void FromProtobuf(const proto::Region& proto);
+
   class CC_EXPORT Iterator {
    public:
     Iterator();
     explicit Iterator(const Region& region);
     ~Iterator();
 
     gfx::Rect rect() const {
       return gfx::SkIRectToRect(it_.rect());
     }
 
@@ skipping 53 matching lines @@
 
 inline Region UnionRegions(const Region& a, const gfx::Rect& b) {
   Region result = a;
   result.Union(b);
   return result;
 }
 
 }  // namespace cc
 
 #endif  // CC_BASE_REGION_H_