Remove Google Storage scheme prefix correctly from gs base name in webpages_playback

tools/skp/webpages_playback.py

 #!/usr/bin/env python
 # 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.
 
 """Archives or replays webpages and creates SKPs in a Google Storage location.
 
 To archive webpages and store SKP files (archives should be rarely updated):
 
 cd ../buildbot/slave/skia_slave_scripts
@@ skipping 91 matching lines @@
 CREDENTIALS_GS_PATH = '/playback/credentials/credentials.json'
 
 X11_DISPLAY = os.getenv('DISPLAY', ':0')
 
 GS_PREDEFINED_ACL = gs_utils.GSUtils.PredefinedACL.PRIVATE
 GS_FINE_GRAINED_ACL_LIST = [
   (gs_utils.GSUtils.IdType.GROUP_BY_DOMAIN, 'google.com',
    gs_utils.GSUtils.Permission.READ),
 ]
 
+def remove_prefix(s, prefix):
+  if s.startswith(prefix):
+    return s[len(prefix):]
+  return s
 
 class SkPicturePlayback(object):
   """Class that archives or replays webpages and creates SKPs."""
 
   def __init__(self, parse_options):
     """Constructs a SkPicturePlayback BuildStep instance."""
     assert parse_options.browser_executable, 'Must specify --browser_executable'
     self._browser_executable = parse_options.browser_executable
 
     self._all_page_sets_specified = parse_options.page_sets == 'all'
@@ skipping 48 matching lines @@
           "password": "google_testing_account_password"
         },
         "facebook": {
           "username": "facebook_testing_account_username",
           "password": "facebook_testing_account_password"
         }
       }\n\n""" % CREDENTIALS_FILE_PATH
       raw_input("Please press a key when you are ready to proceed...")
     elif not os.path.isfile(CREDENTIALS_FILE_PATH):
       # Download the credentials.json file from Google Storage.
-      gs_bucket = self._dest_gsbase.lstrip(gs_utils.GS_PREFIX)
+      gs_bucket = remove_prefix(self._dest_gsbase.lstrip(), gs_utils.GS_PREFIX)
       gs_utils.GSUtils().download_file(gs_bucket, CREDENTIALS_GS_PATH,
                                        CREDENTIALS_FILE_PATH)
 
     # Delete any left over data files in the data directory.
     for archive_file in glob.glob(
         os.path.join(LOCAL_REPLAY_WEBPAGES_ARCHIVE_DIR, 'skia_*')):
       os.remove(archive_file)
 
     # Delete the local root directory if it already exists.
     if os.path.exists(LOCAL_PLAYBACK_ROOT_DIR):
@@ skipping 121 matching lines @@
 
     print '\n\n'
 
     if not self._skip_all_gs_access and self._upload_to_gs:
       print '\n\n=======Uploading to Google Storage=======\n\n'
       # Copy the directory structure in the root directory into Google Storage.
       dest_dir_name = ROOT_PLAYBACK_DIR_NAME
       if self._alternate_upload_dir:
         dest_dir_name = self._alternate_upload_dir
 
-      gs_bucket = self._dest_gsbase.lstrip(gs_utils.GS_PREFIX)
+      gs_bucket = remove_prefix(self._dest_gsbase.lstrip(), gs_utils.GS_PREFIX)
       gs_utils.GSUtils().upload_dir_contents(
           LOCAL_PLAYBACK_ROOT_DIR, gs_bucket, dest_dir_name,
           upload_if=gs_utils.GSUtils.UploadIf.IF_MODIFIED,
           predefined_acl=GS_PREDEFINED_ACL,
           fine_grained_acl_list=GS_FINE_GRAINED_ACL_LIST)
 
       print '\n\n=======New SKPs have been uploaded to %s =======\n\n' % (
           posixpath.join(self._dest_gsbase, dest_dir_name, SKPICTURES_DIR_NAME))
     else:
       print '\n\n=======Not Uploading to Google Storage=======\n\n'
@@ skipping 42 matching lines @@
       os.makedirs(d)
 
   def _DownloadWebpagesArchive(self, wpr_data_file, page_set_json_name):
     """Downloads the webpages archive and its required page set from GS."""
     wpr_source = posixpath.join(ROOT_PLAYBACK_DIR_NAME, 'webpages_archive',
                                 wpr_data_file)
     page_set_source = posixpath.join(ROOT_PLAYBACK_DIR_NAME,
                                      'webpages_archive',
                                      page_set_json_name)
     gs = gs_utils.GSUtils()
-    gs_bucket = self._dest_gsbase.lstrip(gs_utils.GS_PREFIX)
+    gs_bucket = remove_prefix(self._dest_gsbase.lstrip(), gs_utils.GS_PREFIX)
     if (gs.does_storage_object_exist(gs_bucket, wpr_source) and
         gs.does_storage_object_exist(gs_bucket, page_set_source)):
       gs.download_file(gs_bucket, wpr_source,
                        os.path.join(LOCAL_REPLAY_WEBPAGES_ARCHIVE_DIR,
                                     wpr_data_file))
       gs.download_file(gs_bucket, page_set_source,
                        os.path.join(LOCAL_REPLAY_WEBPAGES_ARCHIVE_DIR,
                                     page_set_json_name))
     else:
       raise Exception('%s and %s do not exist in Google Storage!' % (
@@ skipping 53 matching lines @@
       default=None)
   option_parser.add_option(
       '', '--non-interactive', action='store_true',
       help='Runs the script without any prompts. If this flag is specified and '
            '--skia_tools is specified then the debugger is not run.',
       default=False)
   options, unused_args = option_parser.parse_args()
 
   playback = SkPicturePlayback(options)
   sys.exit(playback.Run())