Enable smoothness.tough_pinch_zoom_cases on Chrome OS

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 benchmarks import silk_flags
 import page_sets
 from measurements import smoothness
 from telemetry import benchmark
 
 
@@ skipping 85 matching lines @@
   page_set = page_sets.KeyMobileSitesSmoothPageSet
   def CustomizeBrowserOptions(self, options):
     silk_flags.CustomizeBrowserOptionsForSyncScrolling(options)
 
 @benchmark.Enabled('android')
 class SmoothnessSimpleMobilePages(benchmark.Benchmark):
   """Measures rendering statistics for simple mobile sites page set """
   test = smoothness.Smoothness
   page_set = page_sets.SimpleMobileSitesPageSet
 
-@benchmark.Enabled('android')
+@benchmark.Enabled('android', 'chromeos')
 class SmoothnessToughPinchZoomCases(benchmark.Benchmark):
   """Measures rendering statistics for pinch-zooming into the tough pinch zoom
   cases
   """
   test = smoothness.Smoothness
   page_set = page_sets.ToughPinchZoomCasesPageSet
 
 
 @benchmark.Enabled('android')
 class SmoothnessPolymer(benchmark.Benchmark):
@@ skipping 33 matching lines @@
 class SmoothnessGpuImageDecodingCases(benchmark.Benchmark):
   """Measures decoding statistics for jpeg images with GPU rasterization
   """
   tag = 'gpu_rasterization_and_decoding'
   test = smoothness.Smoothness
   page_set = page_sets.ImageDecodingCasesPageSet
   def CustomizeBrowserOptions(self, options):
     silk_flags.CustomizeBrowserOptionsForGpuRasterization(options)
     # TODO: Remove the following line once M41 goes stable
     options.AppendExtraBrowserArgs('--enable-accelerated-jpeg-decoding')
-