[Bookmark Manager] Add first meaningful paint metric to bookmark manager.

chrome/browser/resources/bookmark_manager/js/main.js

 // Copyright (c) 2012 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.
 
 (function() {
 'use strict';
 
 /** @const */ var BookmarkList = bmm.BookmarkList;
 /** @const */ var BookmarkTree = bmm.BookmarkTree;
 /** @const */ var Command = cr.ui.Command;
@@ skipping 53 matching lines @@
 
 /**
  * @type {TreeItem}
  * @const
  */
 var searchTreeItem = new TreeItem({
   bookmarkId: 'q='
 });
 
 /**
+ * @type {boolean}
+ */
+var firstLoad = true;
+
+/**
  * Command shortcut mapping.
  * @const
  */
 var commandShortcutMap = cr.isMac ? {
   'edit': 'Enter',
   // On Mac we also allow Meta+Backspace.
   'delete': 'Delete Backspace Meta|Backspace',
   'open-in-background-tab': 'Meta|Enter',
   'open-in-new-tab': 'Shift|Meta|Enter',
   'open-in-same-window': 'Meta|Down',
@@ skipping 100 matching lines @@
   bmm.list.parentId = id;
 
   // When tree.selectedItem changed, tree view calls navigatTo() then it
   // calls updateHash() when list view displayed specified folder.
   bmm.tree.selectedItem = bmm.treeLookup[id] || bmm.tree.selectedItem;
 }
 
 // Process the location hash. This is called by onhashchange and when the page
 // is first loaded.
 function processHash() {
+  var wasFirstLoad = firstLoad;
+  firstLoad = false;
   var id = window.location.hash.slice(1);
   if (!id) {
     // If we do not have a hash, select first item in the tree.
     id = bmm.tree.items[0].bookmarkId;
   }
 
   var valid = false;
   if (/^e=/.test(id)) {
     id = id.slice(2);
 
@@ skipping 29 matching lines @@
   }
 
   // Navigate to bookmark 'id' (which may be a query of the form q=query).
   if (valid) {
     updateParentId(id);
   } else {
     // We need to verify that this is a correct ID.
     chrome.bookmarks.get(id, function(items) {
       if (items && items.length == 1)
         updateParentId(id);
+
+      if (wasFirstLoad) {
+        setTimeout(function() {
+          chrome.metricsPrivate.recordTime(
+              'BookmarkManager.ResultsRenderedTime',
+              Math.floor(window.performance.now()));
+        });
+      }
     });
   }
 }
 
 // Activate is handled by the open-in-same-window-command.
 function handleDoubleClickForList(e) {
   if (e.button == 0)
     $('open-in-same-window-command').execute();
 }
 
@@ skipping 1274 matching lines @@
 
   cr.ui.FocusOutlineManager.forDocument(document);
   initializeSplitter();
   bmm.addBookmarkModelListeners();
   dnd.init(selectItemsAfterUserAction);
   bmm.tree.reload();
 }
 
 initializeBookmarkManager();
 })();