[chrome_remote_control] Use monkey patching for stubs.

tools/chrome_remote_control/chrome_remote_control/cros_browser_finder.py

Index: tools/chrome_remote_control/chrome_remote_control/cros_browser_finder.py
diff --git a/tools/chrome_remote_control/chrome_remote_control/cros_browser_finder.py b/tools/chrome_remote_control/chrome_remote_control/cros_browser_finder.py
index 993560cabaeb378b7a58f254b52c59371d6ff897..e034609eeef9959db807ac79bdc9fee50d683a99 100644
--- a/tools/chrome_remote_control/chrome_remote_control/cros_browser_finder.py
+++ b/tools/chrome_remote_control/chrome_remote_control/cros_browser_finder.py
@@ -1,16 +1,16 @@
 # 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 sys as real_sys
-import subprocess as real_subprocess
 import logging
+import os
 import re
+import subprocess
+import sys
 
 import browser
-import possible_browser
 import cros_browser_backend
-import cros_interface as real_cros_interface
+import cros_interface
+import possible_browser
 
 """Finds android browsers that can be controlled by chrome_remote_control."""
 
@@ -33,9 +33,7 @@ class PossibleCrOSBrowser(possible_browser.PossibleBrowser):
         self.browser_type, self._options, *self._args)
     return browser.Browser(backend)
 
-def FindAllAvailableBrowsers(options,
-                             subprocess = real_subprocess,
-                             cros_interface = real_cros_interface):
+def FindAllAvailableBrowsers(options):
   """Finds all the desktop browsers available on this machine."""
   if options.cros_remote == None:
     logging.debug('No --remote specified, will not probe for CrOS.')