Refactor _IsValidPrivacyBucket.

tools/telemetry/telemetry/page/page_set.py

 # Copyright 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 csv
 import inspect
 import os
 
 from telemetry.page import page as page_module
 from telemetry.page import page_set_archive_info
@@ skipping 57 matching lines @@
 
   def AddPageWithDefaultRunNavigate(self, page_url):
     """ Add a simple page with url equals to page_url that contains only default
     RunNavigateSteps.
     """
     self.AddUserStory(page_module.Page(
       page_url, self, self.base_dir))
 
   @staticmethod
   def _IsValidPrivacyBucket(bucket_name):
-    if not bucket_name:
-      return True
-    if (bucket_name in [PUBLIC_BUCKET, PARTNER_BUCKET, INTERNAL_BUCKET]):
-      return True
-    return False
+    return bucket_name in (None, PUBLIC_BUCKET, PARTNER_BUCKET, INTERNAL_BUCKET)
 
   @property
   def base_dir(self):
     if os.path.isfile(self.file_path):
       return os.path.dirname(self.file_path)
     else:
       return self.file_path
 
   @property
   def wpr_archive_info(self):  # pylint: disable=E0202
@@ skipping 39 matching lines @@
           self.AddPage(page_set_dict[csv_row[url_index]])
         else:
           raise Exception('Unusable results_file.')
 
     return user_stories
 
   def WprFilePathForPage(self, page):
     if not self.wpr_archive_info:
       return None
     return self.wpr_archive_info.WprFilePathForPage(page)