Revert of Disable smoothness.top_25_smooth on win/mac/linux.

tools/perf/benchmarks/smoothness.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 core import perf_benchmark
 
 from benchmarks import silk_flags
 from benchmarks import webgl_expectations
 from measurements import smoothness
 import page_sets
 import page_sets.key_silk_cases
 from telemetry import benchmark
 
 
-@benchmark.Disabled('win', 'mac', 'linux')  # crbug.com/510818
 class SmoothnessTop25(perf_benchmark.PerfBenchmark):
   """Measures rendering statistics while scrolling down the top 25 web pages.
 
   http://www.chromium.org/developers/design-documents/rendering-benchmarks
   """
   test = smoothness.Smoothness
   page_set = page_sets.Top25SmoothPageSet
 
   @classmethod
   def Name(cls):
@@ skipping 374 matching lines @@
 
 @benchmark.Disabled('reference')  # http://crbug.com/496684
 class SmoothnessToughAdCases(perf_benchmark.PerfBenchmark):
   """Measures rendering statistics while displaying advertisements."""
   test = smoothness.Smoothness
   page_set = page_sets.ToughAdCasesPageSet
 
   @classmethod
   def Name(cls):
     return 'smoothness.tough_ad_cases'