anchor.diff:      var androidBrowserCreationMapping = {
         'chromeOnAndroid' : (AdbDevice device) => new AndroidChrome(device),
         'ContentShellOnAndroid' : (AdbDevice device) =>
  -          new AndroidBrowser(device, contentShellOnAndroidConfig),
  +          new AndroidBrowser(device, contentShellOnAndroidConfig, checkedMode),
         'DartiumOnAndroid' : (AdbDevice device) =>
  -          new AndroidBrowser(device, dartiumOnAndroidConfig),
  +          new AndroidBrowser(device, dartiumOnAndroidConfig, checkedMode),
       };
       if (androidBrowserCreationMapping.containsKey(browserName)) {
         AdbHelper.listDevices().then((deviceIds) {
  
positive.code: 
  /**
   * Encapsulates all the functionality for running tests in browsers.
   * The interface is rather simple. After starting the runner tests
   * are simply added to the queue and a the supplied callbacks are called
   * whenever a test completes.
   */
  
negative.code: 
  
  class AndroidBrowser extends Browser {
    final bool checkedMode;
    AdbDevice _adbDevice;
    AndroidBrowserConfig _config;
  
    AndroidBrowser(this._adbDevice, this._config, this.checkedMode);
  
    Future<bool> start(String url) {
      var intent = new Intent(
  