[filebrowser] Historgram for the file browser's open time.

chrome/browser/resources/file_manager/js/main.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.
 
 /**
  * Global fileManager reference useful for poking at from the console.
  */
 var fileManager;
 
 /**
  * Kick off the file manager dialog.
  *
  * Called by main.html after the dom has been parsed.
  */
 function init() {
   var rootPaths = ['Downloads', 'removable', 'archive', 'tmp'];
 
   function onEntriesFound(filesystem, entries) {
+    metrics.recordTime('EnumerateRoots');
     FileManager.initStrings(function () {
+      metrics.startInterval('Construct');
       fileManager = new FileManager(document.body, filesystem, entries);
+      metrics.recordTime('Construct');
+      metrics.recordTime('TotalLoad');
       // We're ready to run.  Tests can monitor for this state with
       // ExtensionTestMessageListener listener("ready");
       // ASSERT_TRUE(listener.WaitUntilSatisfied());
       chrome.test.sendMessage('ready');
     });
   }
 
   function onFileSystemFound(filesystem) {
+    metrics.recordTime('RequestLocalFileSystem');
     console.log('Found filesystem: ' + filesystem.name, filesystem);
 
     var entries = [];
 
     function onPathError(path, err) {
       console.error('Error locating root path: ' + path + ': ' + err);
     }
 
     function onEntryFound(entry) {
       if (entry) {
         entries.push(entry);
       } else {
         onEntriesFound(filesystem, entries);
       }
     }
 
+    metrics.startInterval('EnumerateRoots');
     if (filesystem.name.match(/^chrome-extension_\S+:external/i)) {
       // We've been handed the local filesystem, whose root directory
       // cannot be enumerated.
       util.getDirectories(filesystem.root, {create: false}, rootPaths,
                           onEntryFound, onPathError);
     } else {
       util.forEachDirEntry(filesystem.root, onEntryFound);
     }
   };
 
   util.installFileErrorToString();
 
-  console.log('Requesting filesystem.');
-  chrome.fileBrowserPrivate.requestLocalFileSystem(onFileSystemFound);
+    console.log('Requesting filesystem.');
+    metrics.startInterval('RequestLocalFileSystem');
+    chrome.fileBrowserPrivate.requestLocalFileSystem(onFileSystemFound);
 }