[chrome_remote_control] Add pylint to PRESUMMIT and fix lint

tools/chrome_remote_control/chrome_remote_control/desktop_browser_finder.py

 # Copyright (c) 2012 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.
+"""Finds desktop browsers that can be controlled by chrome_remote_control."""
+
 import logging
 import os as real_os
 import sys as real_sys
 import subprocess as real_subprocess
 
 from chrome_remote_control import browser
 from chrome_remote_control import desktop_browser_backend
 from chrome_remote_control import possible_browser
 
-"""Finds desktop browsers that can be controlled by chrome_remote_control."""
-
 ALL_BROWSER_TYPES = ','.join([
     'exact',
     'release',
     'debug',
     'canary',
     'content-shell-debug',
     'content-shell-release',
     'system'])
 
 class PossibleDesktopBrowser(possible_browser.PossibleBrowser):
@@ skipping 106 matching lines @@
     if os.path.exists(win_system):
       browsers.append(PossibleDesktopBrowser('system', options,
                                              win_system, False))
 
   if len(browsers) and not has_display:
     logging.warning('Found (%s), but you have a DISPLAY environment set.' %
                     ','.join([b.browser_type for b in browsers]))
     return []
 
   return browsers