[telemetry] Sort imports in Telemetry and its dependents.

tools/perf/measurements/page_cycler_unittest.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 sys
 import unittest
 
-from metrics import keychain_metric
 from telemetry.core import browser_options
 from telemetry.results import page_test_results
 from telemetry.unittest_util import simple_mock
 from telemetry.user_story import user_story_runner
 
 from measurements import page_cycler
+from metrics import keychain_metric
 
 
 # Allow testing protected members in the unit test.
 # pylint: disable=W0212
 
 class MockMemoryMetric(object):
   """Used instead of simple_mock.MockObject so that the precise order and
   number of calls need not be specified."""
   def __init__(self):
     pass
@@ skipping 227 matching lines @@
     # does an initial navigate to avoid paying for a cross-renderer navigation.
     cycler = self.SetUpCycler(setup_memory_module=True)
     pages = [FakePage('file://fakepage1.com'), FakePage('file://fakepage2.com')]
     tab = FakeTab()
 
     self.assertEqual([], tab.navigated_urls)
     for page in pages * 2:
       cycler.WillNavigateToPage(page, tab)
       self.assertEqual(
           ['http://fakeserver:99999/nonexistent.html'], tab.navigated_urls)