Add one benchmark to get CPU and memory usage without MR.

chrome/test/media_router/telemetry/benchmarks/media_router_benchmark.py

 # Copyright 2016 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.
 
 import os
 from telemetry import benchmark
 from core import perf_benchmark
 from core import path_util
 from telemetry.timeline import tracing_category_filter
 from telemetry.web_perf import timeline_based_measurement
@@ skipping 21 matching lines @@
             'Release', 'mr_extension', 'release'),
              os.path.join(path_util.GetChromiumSrcDir(), 'out',
              'Release', 'media_router', 'test_extension')]),
         '--whitelisted-extension-id=enhhojjnijigcajfphajepfemndkmdlo',
         '--media-router=1',
         '--enable-stats-collection-bindings'
     ])
 
 
 class TraceEventCastBenckmark(_BaseCastBenchmark):
+  """Benchmark for dialog latency from trace event."""
 
   def CreateTimelineBasedMeasurementOptions(self):
     media_router_category = 'media_router'
     category_filter = tracing_category_filter.TracingCategoryFilter(
         media_router_category)
     category_filter.AddIncludedCategory('blink.console')
     options = timeline_based_measurement.Options(category_filter)
     options.SetLegacyTimelineBasedMetrics([
         media_router_timeline_metric.MediaRouterMetric()])
     return options
 
   @classmethod
   def Name(cls):
     return 'media_router.dialog.latency.tracing'
 
   @classmethod
   def ValueCanBeAddedPredicate(cls, value, is_first_result):
     """Only drops the first result."""
     return not is_first_result
 
 
 class HistogramCastBenckmark(_BaseCastBenchmark):
+  """Benchmark for dialog latency from histograms."""
 
   def CreatePageTest(self, options):
     return media_router_measurements.MediaRouterDialogTest()
 
   @classmethod
   def Name(cls):
     return 'media_router.dialog.latency.histogram'
 
   @classmethod
   def ValueCanBeAddedPredicate(cls, value, is_first_result):
     """Only drops the first result."""
     return not is_first_result
 
 
 class CPUMemoryCastBenckmark(_BaseCastBenchmark):
+  """Benchmark for CPU and memory usage with Media Router."""
+
   options = {'page_repeat': 1}
 
   page_set = media_router_perf_pages.MediaRouterCPUMemoryPageSet
 
   def CreatePageTest(self, options):
     return media_router_measurements.MediaRouterCPUMemoryTest()
 
   @classmethod
   def Name(cls):
     return 'media_router.cpu_memory'
+
+
+class CPUMemoryBenckmark(perf_benchmark.PerfBenchmark):
+  """Benchmark for CPU and memory usage without Media Router."""
+
+  options = {'page_repeat': 1}
+
+  page_set = media_router_perf_pages.CPUMemoryPageSet
+
+  def SetExtraBrowserOptions(self, options):
+    options.clear_sytem_cache_for_browser_and_profile_on_start = True
+    # This flag is required to enable the communication between the page and
+    # the test extension.
+    options.disable_background_networking = False
+    options.AppendExtraBrowserArgs([
+        '--load-extension=' +

[imcheng, 2016/05/12 20:57:08]

1) we don't need to load the extension if MR is disabled
2) prefer explicitly setting --media-router=0

[Lei Lei, 2016/05/12 21:07:14]

1), it doesn't load MR extension, it only loads the test extension which is
needed to collect cpu and memory usage. For MR on case, we need to load 2
extensions, one is MR extension, another is the test extension. With MR off, we
only need to load test extension.

2) Done.

+             os.path.join(path_util.GetChromiumSrcDir(), 'out',
+             'Release', 'media_router', 'test_extension'),
+        '--enable-stats-collection-bindings'
+    ])
+
+  def CreatePageTest(self, options):
+    return media_router_measurements.MediaRouterCPUMemoryTest()
+
+  @classmethod
+  def Name(cls):
+    return 'media_router.cpu_memory.no_media_router'