Make MediaMetric a subclass of Metric

BUG=

Review URL: https://chromiumcodereview.appspot.com/22298004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@216015 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 40 insertions, 40 deletions

diff --git a/tools/perf/measurements/media.py b/tools/perf/measurements/media.py
index 5ac2048..4d2ffcf 100644
--- a/tools/perf/measurements/media.py
+++ b/tools/perf/measurements/media.py
@@ -2,22 +2,18 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-"""Media measurement class gathers media related metrics on a page set.
-
-Media metrics recorded are controlled by metrics/media.js.  At the end of the
-test each metrics for every media element in the page are reported.
-"""
-import metrics.media
-
+from metrics import media
 from telemetry.page import page_measurement
 
-
 class Media(page_measurement.PageMeasurement):
-  """Provide general video and audio metrics."""
+  """The MediaMeasurement class gathers media-related metrics on a page set.
 
+  Media metrics recorded are controlled by metrics/media.js.  At the end of the
+  test each metric for every media element in the page are reported.
+  """
   def __init__(self):
     super(Media, self).__init__('media_metrics')
-    self.metrics = None
+    self._media_metric = None
 
   def results_are_the_same_on_every_page(self):
     """Results can vary from page to page based on media events taking place."""
@@ -25,9 +21,10 @@ class Media(page_measurement.PageMeasurement):
 
   def DidNavigateToPage(self, page, tab):
     """Override to do operations right after the page is navigated."""
-    self.metrics = metrics.media.MediaMetrics(tab)
-    self.metrics.Start()
+    self._media_metric = media.MediaMetric(tab)
+    self._media_metric.Start(page, tab)
 
   def MeasurePage(self, page, tab, results):
     """Measure the page's performance."""
-    self.metrics.StopAndGetResults(results)
+    self._media_metric.Stop(page, tab)
+    self._media_metric.AddResults(tab, results)
diff --git a/tools/perf/metrics/media.py b/tools/perf/metrics/media.py
index 3f3df23..282c9bd 100644
--- a/tools/perf/metrics/media.py
+++ b/tools/perf/metrics/media.py
@@ -1,37 +1,39 @@
 # 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.
-
-"""Media Metrics class injects and calls JS responsible for recording metrics.
-
-Default media metrics are collected for every media element in the page, such as
-decoded_frame_count, dropped_frame_count, decoded_video_bytes, and
-decoded_audio_bytes.
-"""
-
 import logging
 import os
 
+from metrics import Metric
 
-class MediaMetrics(object):
+class MediaMetric(Metric):
+  """MediaMetric class injects and calls JS responsible for recording metrics.
+
+  Default media metrics are collected for every media element in the page,
+  such as decoded_frame_count, dropped_frame_count, decoded_video_bytes, and
+  decoded_audio_bytes.
+  """
   def __init__(self, tab):
-    with open(
-        os.path.join(os.path.dirname(__file__), 'media.js')) as f:
+    super(MediaMetric, self).__init__()
+    with open(os.path.join(os.path.dirname(__file__), 'media.js')) as f:
       js = f.read()
       tab.ExecuteJavaScript(js)
-    self.tab = tab
+    self._results = None
 
-  def Start(self):
+  def Start(self, page, tab):
     """Create the media metrics for all media elements in the document."""
-    self.tab.ExecuteJavaScript('window.__createMediaMetricsForDocument()')
+    tab.ExecuteJavaScript('window.__createMediaMetricsForDocument()')
+
+  def Stop(self, page, tab):
+    self._results = tab.EvaluateJavaScript('window.__getAllMetrics()')
 
-  def StopAndGetResults(self, results):
+  def AddResults(self, tab, results):
     """Reports all recorded metrics as Telemetry perf results."""
-    media_metrics = self.tab.EvaluateJavaScript('window.__getAllMetrics()')
-    for media_metric in media_metrics:
-      self.AddResultsForMediaElement(media_metric, results)
+    assert self._results
+    for media_metric in self._results:
+      self._AddResultsForMediaElement(media_metric, results)
 
-  def AddResultsForMediaElement(self, media_metric, results):
+  def _AddResultsForMediaElement(self, media_metric, results):
     """Reports metrics for one media element.
 
     Media metrics contain an ID identifying the media element and values:
@@ -44,7 +46,7 @@ class MediaMetrics(object):
       }
     }
     """
-    def AddResults(metric, unit):
+    def AddOneResult(metric, unit):
       metrics = media_metric['metrics']
       for m in metrics:
         if m.startswith(metric):
@@ -56,10 +58,11 @@ class MediaMetrics(object):
     if not trace:
       logging.error('Metrics ID is missing in results.')
       return
-    AddResults('decoded_audio_bytes', 'bytes')
-    AddResults('decoded_video_bytes', 'bytes')
-    AddResults('decoded_frame_count', 'frames')
-    AddResults('dropped_frame_count', 'frames')
-    AddResults('playback_time', 'sec')
-    AddResults('seek', 'sec')
-    AddResults('time_to_play', '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')
+