Add source column to chrome://policy showing the origins of policies.

chrome/browser/resources/policy.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.
 cr.define('policy', function() {
 
   /**
    * A hack to check if we are displaying the mobile version of this page by
    * checking if the first column is hidden.
    * @return {boolean} True if this is the mobile version.
    */
@@ skipping 116 matching lines @@
 
       // Populate the remaining columns with policy scope, level and value if a
       // value has been set. Otherwise, leave them blank.
       if (value) {
         this.querySelector('.scope').textContent =
             loadTimeData.getString(value.scope == 'user' ?
                 'scopeUser' : 'scopeDevice');
         this.querySelector('.level').textContent =
             loadTimeData.getString(value.level == 'recommended' ?
                 'levelRecommended' : 'levelMandatory');
+        this.querySelector('.source').textContent =
+            loadTimeData.getString(value.source);
         this.querySelector('.value').textContent = value.value;
         this.querySelector('.expanded-value').textContent = value.value;
       }
 
       // Populate the status column.
       var status;
       if (!value) {
         // If the policy value has not been set, show an error message.
         status = loadTimeData.getString('unset');
       } else if (unknown) {
@@ skipping 365 matching lines @@
     },
 
     /**
      * Creates a new table for displaying policies.
      * @return {Element} The newly created table.
      */
     createPolicyTable: function() {
       var newTable = window.document.createElement('table');
       var tableHead = window.document.createElement('thead');
       var tableRow = window.document.createElement('tr');
-      var tableHeadings = ['Scope', 'Level', 'Name', 'Value', 'Status'];
+      var tableHeadings = ['Scope', 'Level', 'Source', 'Name', 'Value',
+          'Status'];
       for (var i = 0; i < tableHeadings.length; i++) {
         var tableHeader = window.document.createElement('th');
         tableHeader.classList.add(tableHeadings[i].toLowerCase() + '-column');
         tableHeader.textContent = loadTimeData.getString('header' +
                                                          tableHeadings[i]);
         tableRow.appendChild(tableHeader);
       }
       tableHead.appendChild(tableRow);
       newTable.appendChild(tableHead);
       cr.ui.decorate(newTable, PolicyTable);
@@ skipping 36 matching lines @@
   return {
     Page: Page
   };
 });
 
 // Have the main initialization function be called when the page finishes
 // loading.
 document.addEventListener(
     'DOMContentLoaded',
     policy.Page.getInstance().initialize.bind(policy.Page.getInstance()));