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

mojo/public/bindings/sample/sample_service.idl

 // Copyright 2013 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.
 
 // HYPOTHETICAL IDL:
 
 module sample {
 
 struct Bar {
   uint8 alpha @0;
   uint8 beta @1;
   uint8 gamma @2;
 };
 
 [RequiredFields=7]
 struct Foo {
   string name @8;
   int32 x @0;
   int32 y @1;
   bool a @2;
   bool b @3;
   bool c @4;
   Bar bar @5;
   Bar[] extra_bars @7;
   uint8[] data @6;
   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;
+};
+
 }