Measure video stats for WebRTC calls to ensure video works.

tools/perf/metrics/media.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.
 import logging
 import os
 
 from metrics import Metric
 from telemetry.value import list_of_scalar_values
 from telemetry.value import scalar
 
@@ skipping 16 matching lines @@
 
   def Start(self, page, tab):
     """Create the media metrics for all media elements in the document."""
     if hasattr(page, 'skip_basic_metrics'):
       self._skip_basic_metrics = page.skip_basic_metrics
     tab.ExecuteJavaScript('window.__createMediaMetricsForDocument()')
 
   def Stop(self, page, tab):
     self._results = tab.EvaluateJavaScript('window.__getAllMetrics()')
 
-  def AddResults(self, tab, results):
+  # Optional |exclude_metrics| args are not in base class Metric.
+  # pylint: disable=W0221
+  def AddResults(self, tab, results, exclude_metrics=None):
     """Reports all recorded metrics as Telemetry perf results."""
+    exclude_metrics = exclude_metrics or []
     trace_names = []
     for media_metric in self._results:
-      trace_names.append(self._AddResultsForMediaElement(media_metric, results))
+      trace_names.append(self._AddResultsForMediaElement(media_metric, results,
+                                                         exclude_metrics))
 
     return '_'.join(trace_names) or tab.url
 
-  def _AddResultsForMediaElement(self, media_metric, results):
+  def _AddResultsForMediaElement(self, media_metric, results, exclude_metrics):
     """Reports metrics for one media element.
 
     Media metrics contain an ID identifying the media element and values:
     media_metric = {
       'id': 'video_1',
       'metrics': {
           'time_to_play': 120,
           'decoded_bytes': 13233,
           ...
       }
     }
     """
     def AddOneResult(metric, unit):
+      if metric in exclude_metrics:
+        return
+
       metrics = media_metric['metrics']
       for m in metrics:
         if m.startswith(metric):
           special_label = m[len(metric):]
           trace_name = '%s.%s%s' % (metric, trace, special_label)
           if isinstance(metrics[m], list):
             results.AddValue(list_of_scalar_values.ListOfScalarValues(
                 results.current_page, trace_name, unit,
                 values=[float(v) for v in metrics[m]],
                 important=True))
@@ skipping 11 matching lines @@
       AddOneResult('buffering_time', 'ms')
       AddOneResult('decoded_audio_bytes', 'bytes')
       AddOneResult('decoded_video_bytes', 'bytes')
       AddOneResult('decoded_frame_count', 'frames')
       AddOneResult('dropped_frame_count', 'frames')
       AddOneResult('time_to_play', 'ms')
 
     AddOneResult('avg_loop_time', 'ms')
     AddOneResult('seek', 'ms')
     return trace