[telemetry] Sort imports in Telemetry and its dependents.

tools/perf/benchmarks/benchmark_unittest.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.
 
 """For all the benchmarks that set options, test that the options are valid."""
 
+from collections import defaultdict
 import logging
 import os
 import unittest
-from collections import defaultdict
 
 from telemetry import benchmark as benchmark_module
 from telemetry.core import browser_options
 from telemetry.core import discover
 from telemetry.unittest_util import progress_reporter
 
 
 def _GetPerfDir(*subdirs):
   perf_dir = os.path.dirname(os.path.dirname(__file__))
   return os.path.join(perf_dir, *subdirs)
@@ skipping 39 matching lines @@
     setattr(BenchmarkOptionsTest, benchmark.Name(),
             _BenchmarkOptionsTestGenerator(benchmark))
     suite.addTest(BenchmarkOptionsTest(benchmark.Name()))
   suite.addTest(TestNoBenchmarkNamesDuplication())
 
 
 def load_tests(_, _2, _3):
   suite = progress_reporter.TestSuite()
   _AddBenchmarkOptionsTests(suite)
   return suite