Force software rasterization on ThreadTimesCompositorCases benchmark.

tools/perf/benchmarks/thread_times.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.
 
 from benchmarks import silk_flags
 from measurements import thread_times
 import page_sets
 from telemetry import benchmark
 
 
@@ skipping 34 matching lines @@
 
 class ThreadTimesSimpleMobileSites(benchmark.Benchmark):
   """Measures timeline metric using smoothness action on simple mobile sites
   http://www.chromium.org/developers/design-documents/rendering-benchmarks"""
   test = thread_times.ThreadTimes
   page_set = page_sets.SimpleMobileSitesPageSet
 
 
 class ThreadTimesCompositorCases(benchmark.Benchmark):
   """Measures timeline metrics while performing smoothness action on
-  tough compositor cases.
+  tough compositor cases, using software rasterization.
+
   http://www.chromium.org/developers/design-documents/rendering-benchmarks"""
   test = thread_times.ThreadTimes
   page_set = page_sets.ToughCompositorCasesPageSet
-
+  def CustomizeBrowserOptions(self, options):
+    silk_flags.CustomizeBrowserOptionsForSoftwareRasterization(options)
 
 @benchmark.Enabled('android')
 class ThreadTimesPolymer(benchmark.Benchmark):
   """Measures timeline metrics while performing smoothness action on
   Polymer cases."""
   test = thread_times.ThreadTimes
   page_set = page_sets.PolymerPageSet
   options = { 'report_silk_results': True }