Add Telemetry media loop action.

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
 
 class MediaMetric(Metric):
   """MediaMetric class injects and calls JS responsible for recording metrics.
@@ skipping 40 matching lines @@
       for m in metrics:
         if m.startswith(metric):
           special_label = m[len(metric):]
           results.Add(trace + special_label, unit, str(metrics[m]),
                       chart_name=metric, data_type='default')
 
     trace = media_metric['id']
     if not trace:
       logging.error('Metrics ID is missing in results.')
       return
+    AddOneResult('avg_loop_time', 'sec')
     AddOneResult('decoded_audio_bytes', 'bytes')
     AddOneResult('decoded_video_bytes', 'bytes')
     AddOneResult('decoded_frame_count', 'frames')
     AddOneResult('dropped_frame_count', 'frames')
     AddOneResult('playback_time', 'sec')
     AddOneResult('seek', 'sec')
     AddOneResult('time_to_play', 'sec')