tools/benchmarks: Fix failures in image decoding measurements.

tools/perf/benchmarks/image_decoding.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 telemetry import benchmark
 
 from measurements import image_decoding
 import page_sets
 
 
 @benchmark.Owner(emails=['cblume@chromium.org', 'reveman@chromium.org'])
 class ImageDecodingToughImageCases(perf_benchmark.PerfBenchmark):
   test = image_decoding.ImageDecoding
   # TODO: Rename this page set to tough_image_cases.py
   page_set = page_sets.ImageDecodingMeasurementPageSet
 
   @classmethod
   def Name(cls):
     return 'image_decoding.image_decoding_measurement'
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
     # crbug.com/667501
     return possible_browser.platform.GetDeviceTypeName() == 'Nexus 7'
 
   def GetExpectations(self):
     return page_sets.ImageDecodingMeasurementStoryExpectations()
+
+  def SetExtraBrowserOptions(self, options):
+    options.AppendExtraBrowserArgs([
+        # Disable asynchronous decodes in the renderer since these test
+        # rely on images have been decoded between consecutive
+        # requestAnimationFrames.
+        '--disable-checker-imaging'
+    ])