Add a "Save log" button to media-internals

content/browser/resources/media/player_info.js

 // 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.
 
 /**
  * @fileoverview A class for keeping track of the details of a player.
  */
 
 var PlayerInfo = (function() {
   'use strict';
 
   /**
    * A class that keeps track of properties on a media player.
    * @param id A unique id that can be used to identify this player.
    */
   function PlayerInfo(id) {
     this.id = id;
     // The current value of the properties for this player.
     this.properties = {};
-    // All of the past (and present) values of the properties.
-    this.pastValues = {};
 
     // Every single event in the order in which they were received.
     this.allEvents = [];
     this.lastRendered = 0;
 
     this.firstTimestamp_ = -1;
   }
 
   PlayerInfo.prototype = {
     /**
      * Adds or set a property on this player.
      * This is the default logging method as it keeps track of old values.
      * @param timestamp  The time in milliseconds since the Epoch.
      * @param key A String key that describes the property.
      * @param value The value of the property.
      */
     addProperty: function(timestamp, key, value) {
       // The first timestamp that we get will be recorded.
       // Then, all future timestamps are deltas of that.
       if (this.firstTimestamp_ === -1) {
         this.firstTimestamp_ = timestamp;
       }
 
       if (typeof key !== 'string') {
         throw new Error(typeof key + ' is not a valid key type');
       }
 
       this.properties[key] = value;
 
-      if (!this.pastValues[key]) {
-        this.pastValues[key] = [];
-      }
-
       var recordValue = {
         time: timestamp - this.firstTimestamp_,
         key: key,
         value: value
       };
 
-      this.pastValues[key].push(recordValue);
       this.allEvents.push(recordValue);
     },
 
     /**
      * Adds or set a property on this player.
      * Does not keep track of old values.  This is better for
      * values that get spammed repeatedly.
      * @param timestamp The time in milliseconds since the Epoch.
      * @param key A String key that describes the property.
      * @param value The value of the property.
      */
     addPropertyNoRecord: function(timestamp, key, value) {
       this.addProperty(timestamp, key, value);
       this.allEvents.pop();
     }
   };
 
   return PlayerInfo;
 }());