[tools/perf] Enable many more lint checks for perf directory.

tools/perf/page_sets/dual_browser_story.py

 # Copyright 2016 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 collections
 import logging
 import re
 import sys
 import urllib
 
@@ skipping 236 matching lines @@
   """A story set that switches back and forth between two browsers."""
 
   def __init__(self):
     super(DualBrowserStorySet, self).__init__(
         archive_data_file='data/dual_browser_story.json',
         cloud_storage_bucket=story_module.PARTNER_BUCKET)
 
     for query, url in zip(SEARCH_QUERIES, URL_LIST):
       # Stories that run on the android-webview browser.
       self.AddStory(SinglePage(
-          name='google_%s' % re.sub('\W+', '_', query.lower()),
+          name='google_%s' % re.sub(r'\W+', '_', query.lower()),
           url=GOOGLE_SEARCH + urllib.urlencode({'q': query}),
           browser_type='android-webview',
           phase='on_webview'))
 
       # Stories that run on the browser selected by command line options.
       self.AddStory(SinglePage(
-          name=re.sub('\W+', '_', url),
+          name=re.sub(r'\W+', '_', url),
           url=url,
           browser_type='default',
           phase='on_chrome'))