anchor.diff:        'logcat',
         '-v',
         'tag', // Only log the tag and the message
  +      '-T',
  +      device.lastLogcatTimestamp,
         '-s',
         'flutter:V',
         'ActivityManager:W',
  
positive.code:   Future<String> stopTracing(AndroidApk apk, { String outPath }) async {
      // Workaround for logcat -c not always working:
      // http://stackoverflow.com/questions/25645012/logcat-on-android-l-not-clearing-after-unplugging-and-reconnecting
      String beforeStop = lastLogcatTimestamp();
      runCheckedSync(adbCommandForDevice(<String>[
        'shell',
        'am',
  
negative.code: 
    // Return the most recent timestamp in the Android log. The format can be
    // passed to logcat's -T option.
    String get lastLogcatTimestamp {
      String output = runCheckedSync(adbCommandForDevice(<String>[
        '-s', id, 'logcat', '-v', 'time', '-t', '1'
      ]));
  