media: Add "Hide players" button in about://media-internals

content/browser/resources/media/manager.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 Keeps track of all the existing PlayerInfo and
  * audio stream objects and is the entry-point for messages from the backend.
  *
  * The events captured by Manager (add, remove, update) are relayed
  * to the clientRenderer which it can choose to use to modify the UI.
  */
 var Manager = (function() {
   'use strict';
 
   function Manager(clientRenderer) {
     this.players_ = {};
     this.audioComponents_ = [];
     this.clientRenderer_ = clientRenderer;
+
+    this.hidePlayersButton = document.getElementById('hide-players-button');
+    this.hidePlayersButton.onclick = this.hidePlayers_.bind(this);
   }
 
   Manager.prototype = {
     /**
      * Updates an audio-component.
      * @param componentType Integer AudioComponent enum value; must match values
      * from the AudioLogFactory::AudioComponent enum.
      * @param componentId The unique-id of the audio-component.
      * @param componentData The actual component data dictionary.
      */
@@ skipping 42 matching lines @@
     /**
      * Attempts to remove a player from the UI.
      * @param id The ID of the player to remove.
      */
     removePlayer: function(id) {
       var playerRemoved = this.players_[id];
       delete this.players_[id];
       this.clientRenderer_.playerRemoved(this.players_, playerRemoved);
     },
 
+    hidePlayers_: function() {
+      util.object.forEach(this.players_, function(playerInfo, id) {
+        this.removePlayer(id);
+      }, this);
+    },
+
     updatePlayerInfoNoRecord: function(id, timestamp, key, value) {
       if (!this.players_[id]) {
         console.error('[updatePlayerInfo] Id ' + id + ' does not exist');
         return;
       }
 
       this.players_[id].addPropertyNoRecord(timestamp, key, value);
       this.clientRenderer_.playerUpdated(this.players_,
                                          this.players_[id],
                                          key,
@@ skipping 69 matching lines @@
       // The keys of each device to be shown in order of appearance.
       var videoCaptureDeviceKeys = ['name','formats','captureApi','id'];
 
       this.clientRenderer_.redrawVideoCaptureCapabilities(
           videoCaptureCapabilities, videoCaptureDeviceKeys);
     }
   };
 
   return Manager;
 }());