Update perf page_set to use story_set

tools/perf/page_sets/page_reload_cases.py

Index: tools/perf/page_sets/page_reload_cases.py
diff --git a/tools/perf/page_sets/page_reload_cases.py b/tools/perf/page_sets/page_reload_cases.py
index 7642e8572624af9f7094540e8ec09aca46c5fbcb..390586783c4c99f6ccaa8d25291cffd2b92e2440 100644
--- a/tools/perf/page_sets/page_reload_cases.py
+++ b/tools/perf/page_sets/page_reload_cases.py
@@ -1,10 +1,9 @@
 # Copyright 2015 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.
-from telemetry.page import shared_page_state
-from telemetry.page import page_set as page_set_module
-
 from page_sets import top_pages
+from telemetry import story
+from telemetry.page import shared_page_state
 
 
 def _Reload(action_runner):
@@ -26,14 +25,14 @@ def _CreatePageClassWithReload(page_cls):
   return DerivedSmoothPage
 
 
-class PageReloadCasesPageSet(page_set_module.PageSet):
+class PageReloadCasesPageSet(story.StorySet):
 
   """ Pages for testing GC efficiency on page reload. """
 
   def __init__(self):
     super(PageReloadCasesPageSet, self).__init__(
         archive_data_file='data/top_25.json',
-        bucket=page_set_module.PARTNER_BUCKET)
+        cloud_storage_bucket=story.PARTNER_BUCKET)
 
     shared_desktop_state = shared_page_state.SharedDesktopPageState