Mojo: RemotePtr<S> + bindings changes for Peer attribute.

mojo/public/bindings/sample/sample_service.idl

Index: mojo/public/bindings/sample/sample_service.idl
diff --git a/mojo/public/bindings/sample/sample_service.idl b/mojo/public/bindings/sample/sample_service.idl
index 3358a58f07ec02a6c7898eafcbdb17bf00cb1d3e..a1079a518359b973284489e1e37b78da16201691 100644
--- a/mojo/public/bindings/sample/sample_service.idl
+++ b/mojo/public/bindings/sample/sample_service.idl
@@ -26,8 +26,14 @@ struct Foo {
   handle[] files @9;
 };
 
+[Peer=ServiceClient]
 interface Service {
   void Frobinate(Foo foo @0, bool baz @1, handle port @2) @0;
 };
 
+[Peer=Service]
+interface ServiceClient {
+  void DidFrobinate(int32 result @0) @0;
+};
+
 }