Add a new telemetry benchmark to stress-test WebRTC.

tools/perf/measurements/webrtc.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 telemetry.page import legacy_page_test
 
 from metrics import cpu
 from metrics import media
 from metrics import power
 from metrics import webrtc_stats
 
 
 class WebRTC(legacy_page_test.LegacyPageTest):
   """Gathers WebRTC-related metrics on a page set."""
 
-  def __init__(self):
+  def __init__(self, use_webrtc_stats=True):
     super(WebRTC, self).__init__()
     self._cpu_metric = None
     self._media_metric = None
     self._power_metric = None
+    self._use_webrtc_stats = use_webrtc_stats
     self._webrtc_stats_metric = None
 
   def WillStartBrowser(self, platform):
     self._power_metric = power.PowerMetric(platform)
 
   def DidStartBrowser(self, browser):
     self._cpu_metric = cpu.CpuMetric(browser)
-    self._webrtc_stats_metric = webrtc_stats.WebRtcStatisticsMetric()
+    if self._use_webrtc_stats:
+      self._webrtc_stats_metric = webrtc_stats.WebRtcStatisticsMetric()
 
   def DidNavigateToPage(self, page, tab):
     self._cpu_metric.Start(page, tab)
     self._media_metric = media.MediaMetric(tab)
     self._media_metric.Start(page, tab)
     self._power_metric.Start(page, tab)
-    self._webrtc_stats_metric.Start(page, tab)
+    if self._use_webrtc_stats:
+      self._webrtc_stats_metric.Start(page, tab)
 
   def CustomizeBrowserOptions(self, options):
     options.AppendExtraBrowserArgs('--use-fake-device-for-media-stream')
     options.AppendExtraBrowserArgs('--use-fake-ui-for-media-stream')
     power.PowerMetric.CustomizeBrowserOptions(options)
 
   def ValidateAndMeasurePage(self, page, tab, results):
     """Measure the page's performance."""
     self._cpu_metric.Stop(page, tab)
     self._cpu_metric.AddResults(tab, results)
 
     # Add all media metrics except bytes (those aren't hooked up for WebRTC
     # video tags).
     exclude_metrics = ['decoded_video_bytes', 'decoded_audio_bytes']
     self._media_metric.Stop(page, tab)
     self._media_metric.AddResults(tab, results, exclude_metrics=exclude_metrics)
 
     self._power_metric.Stop(page, tab)
     self._power_metric.AddResults(tab, results)
 
-    self._webrtc_stats_metric.Stop(page, tab)
-    self._webrtc_stats_metric.AddResults(tab, results)
+    if self._use_webrtc_stats:
+      self._webrtc_stats_metric.Stop(page, tab)
+      self._webrtc_stats_metric.AddResults(tab, results)
 
   def DidRunPage(self, platform):
     del platform  # unused
     self._power_metric.Close()