Enable testBlinkPerfTracingMetricsForMeasureTime on Win platform

tools/perf/benchmarks/blink_perf_unittest.py

 # Copyright 2017 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 os
 import unittest
 
 from telemetry import decorators
 from telemetry import story
 from telemetry.page import page as page_module
 from telemetry.testing import options_for_unittests
@@ skipping 21 matching lines @@
 
   def _CreateStorySetForTestFile(self, test_file_name):
     story_set = story.StorySet(base_dir=self._BLINK_PERF_TEST_DATA_DIR,
         serving_dirs={self._BLINK_PERF_TEST_DATA_DIR,
                       self._BLINK_PERF_RESOURCES_DIR})
     page = page_module.Page('file://' + test_file_name, story_set,
         base_dir=story_set.base_dir)
     story_set.AddStory(page)
     return story_set
 
-  @decorators.Disabled('win')  # crbug.com/715822
   def testBlinkPerfTracingMetricsForMeasureTime(self):
     results = self.RunMeasurement(measurement=self._measurement,
         ps=self._CreateStorySetForTestFile('append-child-measure-time.html'),
         options=self._options)
     self.assertFalse(results.failures)
     self.assertEquals(len(results.FindAllTraceValues()), 1)
 
     frame_view_layouts = results.FindAllPageSpecificValuesNamed(
         'FrameView::layout')
     self.assertEquals(len(frame_view_layouts), 1)
@@ skipping 121 matching lines @@
     renderer_main.BeginSlice('blink', 'foo', 120)
     renderer_main.EndSlice(140)
 
     renderer_main.BeginSlice('blink', 'bar', 400)
     renderer_main.EndSlice(420)
 
     self.assertEquals(
         blink_perf._ComputeTraceEventsThreadTimeForBlinkPerf(
             renderer_main, ['foo', 'bar']),
         {'foo': [20], 'bar': [20]})