[chromedriver] Catch URLError during buildbot wait_for_snapshot step.

chrome/test/chromedriver/run_buildbot_steps.py

 #!/usr/bin/env python
 # Copyright (c) 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.
 
 """Runs all the buildbot steps for ChromeDriver except for update/compile."""
 
 import bisect
 import csv
 import datetime
@@ skipping 372 matching lines @@
       print 'deleting file', file_path
       os.remove(file_path)
 
 
 def _GetSVNRevisionFromGitHash(snapshot_hashcode):
   json_url = GS_GITHASH_TO_SVN_URL % snapshot_hashcode
   try:
     response = urllib2.urlopen(json_url)
   except urllib2.HTTPError as error:
     util.PrintAndFlush('HTTP Error %d' % error.getcode())
+  except urllib2.URLError as error:
+    util.PrintAndFlush('URL Error %s' % error.message)
     return None
   data = json.loads(response.read()[4:])
   if 'message' in data:
     message = data['message'].split('\n')
     message = [line for line in message if line.strip()]
     search_pattern = re.compile(GS_SEARCH_PATTERN)
     result = search_pattern.search(message[len(message)-1])
     if result:
       return result.group(1)
   util.PrintAndFlush('Failed to get svn revision number for %s' %
@@ skipping 112 matching lines @@
     util.MarkBuildStepStart('run_all_tests.py')
     util.MarkBuildStepError()
 
   # Add a "cleanup" step so that errors from runtest.py or bb_device_steps.py
   # (which invoke this script) are kept in thier own build step.
   util.MarkBuildStepStart('cleanup')
 
 
 if __name__ == '__main__':
   main()