Skip the screenshot_sync test properly.

content/test/gpu/gpu_tests/screenshot_sync.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.
 import os
 import random
 
 from gpu_tests import gpu_test_base
 from gpu_tests import path_util
 from gpu_tests import screenshot_sync_expectations
 
-from telemetry import benchmark
 from telemetry.page import page_test
 from telemetry.story import story_set as story_set_module
 from telemetry.util import image_util
 
 data_path = os.path.join(
     path_util.GetChromiumSrcDir(), 'content', 'test', 'data', 'gpu')
 
 class ScreenshotSyncValidator(gpu_test_base.ValidatorBase):
   def CustomizeBrowserOptions(self, options):
     # --test-type=gpu is used only to suppress the "Google API Keys are missing"
@@ skipping 26 matching lines @@
 class ScreenshotSyncPage(gpu_test_base.PageBase):
   def __init__(self, story_set, base_dir, expectations):
     super(ScreenshotSyncPage, self).__init__(
       url='file://screenshot_sync.html',
       page_set=story_set,
       base_dir=base_dir,
       name='ScreenshotSync',
       expectations=expectations)
 
 
-@benchmark.Disabled('linux', 'mac', 'win')
 class ScreenshotSyncProcess(gpu_test_base.TestBase):
   """Tests that screenhots are properly synchronized with the frame one which
   they were requested"""
   test = ScreenshotSyncValidator
 
   @classmethod
   def Name(cls):
     return 'screenshot_sync'
 
   def _CreateExpectations(self):
     return screenshot_sync_expectations.ScreenshotSyncExpectations()
 
   def CreateStorySet(self, options):
     ps = story_set_module.StorySet(base_dir=data_path, serving_dirs=[''])
     ps.AddStory(ScreenshotSyncPage(ps, ps.base_dir, self.GetExpectations()))
     return ps