Add charts to the resource data section of chrome://media-internals.

chrome/browser/resources/media_internals/disjoint_range_set.js

 // Copyright (c) 2011 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.
 
 cr.define('media', function() {
 
   /**
    * This class represents a collection of non-intersecting ranges. Ranges
    * specified by (start, end) can be added and removed at will. It is used to
    * record which sections of a media file have been cached, e.g. the first and
@@ skipping 107 matching lines @@
       starts.sort(function(a, b) {
         return a - b;
       });
 
       var ranges = this.ranges_;
       var results = starts.map(function(s) {
         return mapper(s, ranges[s]);
       });
 
       return results;
-    }
+    },
+
+    /**
+     * Finds the maximum value present in any of the contained ranges.
+     * @return {int} The maximum value contained by this DisjointRangeSet.
+     */
+    max: function() {
+      var max = -Infinity;
+      for (var start in this.ranges_)
+        max = Math.max(max, this.ranges_[start]);
+      return max;
+    },
   };
 
   return {
     DisjointRangeSet: DisjointRangeSet
   };
 });