Fixes a memory leak when running webrtc-internals for a long time, by using a circular buffer of si…

content/browser/resources/media/stats_graph_helper.js

 // Copyright (c) 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.
 
 //
 // This file contains helper methods to draw the stats timeline graphs.
 // Each graph represents a series of stats report for a PeerConnection,
 // e.g. 1234-0-ssrc-abcd123-bytesSent is the graph for the series of bytesSent
 // for ssrc-abcd123 of PeerConnection 0 in process 1234.
 // The graphs are drawn as CANVAS, grouped per report type per PeerConnection.
@@ skipping 122 matching lines @@
       graphViews[graphViewId] = createStatsGraphView(peerConnectionElement,
                                                      report,
                                                      graphType);
       var date = new Date(stats.timestamp);
       graphViews[graphViewId].setDateRange(date, date);
     }
     // Adds the new dataSeries to the graphView. We have to do it here to cover
     // both the simple and compound graph cases.
     if (!graphViews[graphViewId].hasDataSeries(dataSeries[finalDataSeriesId]))
       graphViews[graphViewId].addDataSeries(dataSeries[finalDataSeriesId]);
+
     graphViews[graphViewId].updateEndDate();
   }
 }
 
 // Makes sure the TimelineDataSeries with id |dataSeriesId| is created,
 // and adds the new data point to it.
 function addDataSeriesPoint(dataSeriesId, time, label, value) {
   if (!dataSeries[dataSeriesId]) {
     dataSeries[dataSeriesId] = new TimelineDataSeries();
     if (bweCompoundGraphConfig[label]) {
@@ skipping 71 matching lines @@
     div.graphViewId =
         peerConnectionElement.id + '-' + reportName + '-bweCompound';
     div.firstChild.addEventListener('click', function(event) {
         var target = dataSeries[event.target.parentNode.dataSeriesId];
         target.show(event.target.checked);
         graphViews[event.target.parentNode.graphViewId].repaint();
     });
   }
   return legend;
 }