[Android] Convert to DeviceUtils versions of IsOnline, HasRoot, and EnableRoot.

tools/android/mempressure.py

 #!/usr/bin/env python
 # 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.
 
 import collections
 import optparse
 import os
 import sys
 
@@ skipping 68 matching lines @@
   if not options.browser in constants.PACKAGE_INFO.keys():
     option_parser.error('Unknown browser option ' + options.browser)
 
   package_info = constants.PACKAGE_INFO[options.browser]
 
   package = package_info.package
   activity = package_info.activity
 
   device = device_utils.DeviceUtils(None)
 
-  device.old_interface.EnableAdbRoot()
+  try:
+    device.EnableRoot()
+  except device_errors.CommandFailedError:
+    # Try to change the flags and start the activity anyway.
+    pass
   flags = flag_changer.FlagChanger(device, package_info.cmdline_file)
   if ENABLE_TEST_INTENTS_FLAG not in flags.Get():
     flags.AddFlags([ENABLE_TEST_INTENTS_FLAG])
 
   device.old_interface.StartActivity(package, activity, action=action)
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))