Wire events through to sample_app

mojo/services/native_viewport/native_viewport.mojom

 // 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.
 
 module mojo {
 
+struct Point {
+  float x;
+  float y;
+};
+
+struct TouchData {
+  int32 pointer_id;
+};
+
+struct Event {
+  int32 action;
+  int64 time_stamp;
+  Point location;
+  TouchData touch_data;
+};
+
 [Peer=NativeViewportClient]
 interface NativeViewport {
   void Open();
   void Close();
   void CreateGLES2Context(handle<message_pipe> gles2_client);
 };
 
 [Peer=NativeViewport]
 interface NativeViewportClient {
   void DidOpen();
+  void HandleEvent(Event event);
 };
 
 }