Explictly setting story names for rasterize_and_record_micro story sets

tools/perf/page_sets/top_pages.py

 # Copyright 2014 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 page as page_module
 from telemetry.page import shared_page_state
 
 
 class TopPages(page_module.Page):
 
   def __init__(self, url, page_set, shared_page_state_class,
                name='', credentials=None):
+    if name == '':
+      name = url
     super(TopPages, self).__init__(
         url=url, page_set=page_set, name=name,
         credentials_path='data/credentials.json',
         shared_page_state_class=shared_page_state_class)
     self.archive_data_file = 'data/top_25.json'
     self.credentials = credentials
 
 
 class GoogleWebSearchPage(TopPages):
 
@@ skipping 264 matching lines @@
   def __init__(self, page_set,
                shared_page_state_class=shared_page_state.SharedPageState):
     super(YahooGamesPage, self).__init__(
         url='http://games.yahoo.com',
         page_set=page_set,
         shared_page_state_class=shared_page_state_class)
 
   def RunNavigateSteps(self, action_runner):
     super(YahooGamesPage, self).RunNavigateSteps(action_runner)
     action_runner.Wait(2)