Move user_story.user_story_set to story.story_set

tools/perf/benchmarks/session_restore.py

 # Copyright 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.
 
 import os
 import tempfile
 
 from telemetry import benchmark
 
 from measurements import session_restore
@@ skipping 37 matching lines @@
         new_args.output_dir = output_dir
         profile_generator.GenerateProfiles(
             small_profile_extender.SmallProfileExtender,
             profile_type, new_args)
       args.browser_options.profile_dir = profile_dir
 
   @classmethod
   def ValueCanBeAddedPredicate(cls, _, is_first_result):
     return cls.tag == 'cold' or not is_first_result
 
-  def CreateUserStorySet(self, _):
-    """Return a user story set that only has the first user story.
+  def CreateStorySet(self, _):
+    """Return a story set that only has the first user story.
 
     The session restore measurement skips the navigation step and
     only tests session restore by having the browser start-up.
     The first user story is used to get WPR set up and hold results.
     """
-    user_story_set = self.page_set()
-    for user_story in user_story_set.user_stories[1:]:
-      user_story_set.RemoveUserStory(user_story)
-    return user_story_set
+    story_set = self.page_set()
+    for user_story in story_set.user_stories[1:]:
+      story_set.RemoveUserStory(user_story)
+    return story_set
 
   def CreatePageTest(self, options):
     is_cold = (self.tag == 'cold')
     return session_restore.SessionRestore(cold=is_cold)
 
   def CreatePageSet(self, options):
     return page_sets.Typical25PageSet(run_no_page_interactions=True)
 
 # crbug.com/325479, crbug.com/381990
 @benchmark.Disabled('android', 'linux', 'reference')
@@ skipping 14 matching lines @@
 
   The first result is discarded.
   """
   tag = 'warm'
   options = {'pageset_repeat': 20}
 
   @classmethod
   def Name(cls):
     return 'session_restore.warm.typical_25'