[ChromeDriver] Added CommandListener interface

chrome/chrome_tests.gypi

 # 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.
 {
   'includes': [
     'js_unittest_vars.gypi',
   ],
   'targets': [
     {
       'target_name': 'interactive_ui_tests',
@@ skipping 599 matching lines @@
         'common/chrome_constants.cc',
         'common/chrome_constants.h',
         'test/chromedriver/alert_commands.cc',
         'test/chromedriver/alert_commands.h',
         'test/chromedriver/basic_types.cc',
         'test/chromedriver/basic_types.h',
         'test/chromedriver/capabilities.cc',
         'test/chromedriver/capabilities.h',
         'test/chromedriver/chrome_launcher.cc',
         'test/chromedriver/chrome_launcher.h',
+        'test/chromedriver/command_listener.cc',
+        'test/chromedriver/command_listener.h',
         'test/chromedriver/command.h',
         'test/chromedriver/commands.cc',
         'test/chromedriver/commands.h',
         'test/chromedriver/element_commands.cc',
         'test/chromedriver/element_commands.h',
         'test/chromedriver/element_util.cc',
         'test/chromedriver/element_util.h',
         'test/chromedriver/key_converter.cc',
         'test/chromedriver/key_converter.h',
         'test/chromedriver/keycode_text_conversion.h',
@@ skipping 2328 matching lines @@
             ['enable_webrtc==1', {
               'dependencies': [
                 '../third_party/libjingle/libjingle.gyp:libjingle_webrtc'
               ]
             }],
           ],
         }]
     }],
   ],  # 'conditions'
 }