[chrome_remote_control] Use monkey patching for stubs.

tools/chrome_remote_control/chrome_remote_control/android_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.
-import os as real_os
-import subprocess as real_subprocess
+import os
 import logging
 import re
+import subprocess
 
+from chrome_remote_control import adb_commands
 from chrome_remote_control import android_browser_backend
-import chrome_remote_control.adb_commands as real_adb_commands
 from chrome_remote_control import browser
 from chrome_remote_control import possible_browser
 
 
 """Finds android browsers that can be controlled by chrome_remote_control."""
 
 ALL_BROWSER_TYPES = ','.join([
     'android-content-shell',
     'android-chrome',
     'android-jb-system-chrome',
@@ skipping 27 matching lines @@
     self._args = args
 
   def __repr__(self):
     return 'PossibleAndroidBrowser(browser_type=%s)' % self.browser_type
 
   def Create(self):
     backend = android_browser_backend.AndroidBrowserBackend(
         self._options, *self._args)
     return browser.Browser(backend)
 
-def FindAllAvailableBrowsers(options,
-                             subprocess=real_subprocess,
-                             adb_commands=real_adb_commands):
+def FindAllAvailableBrowsers(options):
   """Finds all the desktop browsers available on this machine."""
   if not adb_commands.IsAndroidSupported():
     return []
 
   # See if adb even works.
   try:
-    with open(real_os.devnull, 'w') as devnull:
+    with open(os.devnull, 'w') as devnull:
       proc = subprocess.Popen(['adb', 'devices'],
                               stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE,
                               stdin=devnull)
       stdout, _ = proc.communicate()
       if re.search(re.escape('????????????\tno permissions'), stdout) != None:
         logging.warning(
             ('adb devices reported a permissions error. Consider '
             'restarting adb as root:'))
         logging.warning('  adb kill-server')
@@ skipping 63 matching lines @@
     logging.warn('chrome_remote_control detected an android device. However,')
     logging.warn('Chrome\'s port-forwarder app is not installed on the device.')
     logging.warn('To build:')
     logging.warn('  make -j16 out/$BUILDTYPE/forwarder')
     logging.warn('And then install it:')
     logging.warn('  %s', adb_commands.HowToInstallForwarder())
     logging.warn('')
     logging.warn('')
     return []
   return possible_browsers