Fix import order with isort tool.

tools/telemetry/unittest_data/test_page_set.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
 from telemetry.page import page_set
-from telemetry.page import page
+from unittest_data.pages.external_page import ExternalPage
 
-from unittest_data.pages.external_page import ExternalPage
 
 class InternalPage(page.Page):
   def __init__(self, ps):
     super(InternalPage, self).__init__('file://bar.html', page_set=ps)
 
 class TestPageSet(page_set.PageSet):
   """A pageset for testing purpose"""
 
   def __init__(self):
     super(TestPageSet, self).__init__(
       archive_data_file='data/test.json',
       credentials_path='data/credential',
       user_agent_type='desktop',
       bucket=page_set.PUBLIC_BUCKET)
 
     #top google property; a google tab is often open
     class Google(page.Page):
       def __init__(self, ps):
         super(Google, self).__init__('https://www.google.com', page_set=ps)
 
       def RunGetActionRunner(self, action_runner):
         return action_runner
 
     self.AddPage(Google(self))
     self.AddPage(InternalPage(self))
     self.AddPage(ExternalPage(self))