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

cc/base/region.h

Index: cc/base/region.h
diff --git a/cc/base/region.h b/cc/base/region.h
index 583311e09fe007618f133e5084db6183f5ddd288..76eee641199bb0716b1c8908bd718bd9ab1ba8c4 100644
--- a/cc/base/region.h
+++ b/cc/base/region.h
@@ -23,6 +23,10 @@ class TracedValue;
 namespace cc {
 class SimpleEnclosedRegion;
 
+namespace proto {
+class Region;
+}  // namespace proto
+
 class CC_EXPORT Region {
  public:
   Region();
@@ -65,6 +69,9 @@ class CC_EXPORT Region {
   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();