Add Protobuf support in cc for gfx objects

cc/proto/point.proto

Index: cc/proto/point.proto
diff --git a/blimp/common/proto/common.proto b/cc/proto/point.proto
similarity index 59%
copy from blimp/common/proto/common.proto
copy to cc/proto/point.proto
index 578c02b63b78d3b0e09bedfc4582d517d2c263cb..e4598fc9816a6ec34f62d73a693e3296e8bbc3f8 100644
--- a/blimp/common/proto/common.proto
+++ b/cc/proto/point.proto
@@ -1,17 +1,14 @@
 // 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.
-//
-// Common message types for sharing across Blimp subprotocols.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
-package blimp;
+package cc.proto;
 
-message CoordinatePair {
-  optional sint32 x = 1;
-  optional sint32 y = 2;
+message Point {
+  optional int32 x = 1;

[danakj, 2015/10/14 22:42:37]

Is it not problematic that int inside Point can be bigger than 32 bits?

[David Trainor- moved to gerrit, 2015/10/14 22:57:51]

Oops good point :(.  Thanks!  Changed size too and added a unit test against
std::numeric_limits<int> (I think that should test those cases).

+  optional int32 y = 2;

[danakj, 2015/10/14 23:10:10]

why are these all optional? (i'm a noob here)

[David Trainor- moved to gerrit, 2015/10/15 22:18:02]

It's a general rule to never make something required with protobufs.  If you do,
you can't ever do versioning control and omit the field in the future.

 }
-