Revert of [Telemetry] Disable flaky smoothness.top_25 and testRepaint

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 telemetry import test
 
 from benchmarks import silk_flags
 from measurements import smoothness
 import page_sets
 
 
-@test.Disabled  # crbug.com/368767
 class SmoothnessTop25(test.Test):
   """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.Top25PageSet
 
 
 @test.Disabled('linux', 'mac', 'win')  # crbug.com/368767
 class SmoothnessToughCanvasCases(test.Test):
@@ skipping 138 matching lines @@
   """Measures rendering statistics for the Polymer cases with GPU rasterization
   using bleeding edge rendering fast paths.
   """
   tag = 'fast_path_gpu_rasterization'
   test = smoothness.Smoothness
   page_set = page_sets.PolymerPageSet
   def CustomizeBrowserOptions(self, options):
     super(SmoothnessFastPathGpuRasterizationPolymer, self). \
         CustomizeBrowserOptions(options)
     silk_flags.CustomizeBrowserOptionsForFastPath(options)