Add Protobuf support for cc/playback skia usage

cc/proto/skrrect.proto

Index: cc/proto/skrrect.proto
diff --git a/cc/proto/skrrect.proto b/cc/proto/skrrect.proto
new file mode 100644
index 0000000000000000000000000000000000000000..28a8be46ef5b7380fa73dd9529fdaf0c8978111d
--- /dev/null
+++ b/cc/proto/skrrect.proto
@@ -0,0 +1,20 @@
+// 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";
+
+import "pointf.proto";
+import "rectf.proto";
+
+option optimize_for = LITE_RUNTIME;
+
+package cc.proto;
+
+message SkRRect {
+  optional cc.proto.RectF rect = 1;
+  optional cc.proto.PointF radii_upper_left = 2;
+  optional cc.proto.PointF radii_upper_right = 3;
+  optional cc.proto.PointF radii_lower_right = 4;
+  optional cc.proto.PointF radii_lower_left = 5;
+}