[telemetry] Sort imports in Telemetry and its dependents.

tools/perf/benchmarks/startup.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.
 
+from telemetry import benchmark
+
 from measurements import startup
 import page_sets
-from telemetry import benchmark
 
 
 class _StartupCold(benchmark.Benchmark):
   """Measures cold startup time with a clean profile."""
   options = {'pageset_repeat': 5}
 
   @classmethod
   def Name(cls):
     return 'startup'
 
@@ skipping 31 matching lines @@
 
 @benchmark.Enabled('has tabs')
 class StartupWarmBlankPage(_StartupWarm):
   """Measures warm startup time with a clean profile."""
   tag = 'warm'
   page_set = page_sets.BlankPageSet
 
   @classmethod
   def Name(cls):
     return 'startup.warm.blank_page'