Update perf page_set to use story_set

tools/perf/page_sets/new_tab_page.py

Index: tools/perf/page_sets/new_tab_page.py
diff --git a/tools/perf/page_sets/new_tab_page.py b/tools/perf/page_sets/new_tab_page.py
index c3ce4373e5363d643a90232ced9c247a2ef70015..cfcaa2861d415aea8f4bd90af98c6450d8df16a4 100644
--- a/tools/perf/page_sets/new_tab_page.py
+++ b/tools/perf/page_sets/new_tab_page.py
@@ -3,8 +3,8 @@
 # found in the LICENSE file.
 import time
 
+from telemetry import story
 from telemetry.page import page as page_module
-from telemetry.page import page_set as page_set_module
 from telemetry.page import shared_page_state
 
 INTERACTION_NAME = 'Interaction.PageLoading'
@@ -41,9 +41,9 @@ class NewTabPagePage(page_module.Page):
         "console.timeEnd('" + INTERACTION_NAME + "');")
 
 
-class NewTabPagePageSet(page_set_module.PageSet):
+class NewTabPagePageSet(story.StorySet):
   def __init__(self):
     super(NewTabPagePageSet, self).__init__(
         archive_data_file='data/new_tab_page_page.json',
-        bucket=page_set_module.PUBLIC_BUCKET)
+        cloud_storage_bucket=story.PUBLIC_BUCKET)
     self.AddUserStory(NewTabPagePage(page_set=self))