Extract the shell runner into devtools.

examples/dart/speech_input/speech_input.dart

 // 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.
 
-// To run: mojo/tools/mojo_shell.py --sky \
+// To run: mojo/devtools/common/mojo_shell --sky \
 //             examples/dart/speech_input/speech_input.dart --android
 //
 // The speech_recognizer service is only available for Android targets.
 
 import 'package:mojom/speech_recognizer/speech_recognizer.mojom.dart';
 import 'package:sky/mojo/embedder.dart';
 
 import 'package:sky/widgets/raised_button.dart';
 import 'package:sky/widgets/basic.dart';
 
@@ skipping 48 matching lines @@
       new SpeechRecognizerServiceProxy.unbound();
 
   var _result = null;
 
   bool _listening = false;
 }
 
 void main() {
   runApp(new ListenApp());
 }