Change modification date to include time and 'today' and 'yesterday' for appropriate dates.

chrome/browser/resources/file_manager/js/mock_chrome.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 MockEventSource() {
   this.listeners_ = [];
 }
 
 /**
  * Add a listener. There is no remove.
@@ skipping 596 matching lines @@
       RAR_ARCHIVE_FILE_TYPE: 'RAR archive',
       TAR_ARCHIVE_FILE_TYPE: 'Tar archive',
       TAR_BZIP2_ARCHIVE_FILE_TYPE: 'Bzip2 compressed tar archive',
       TAR_GZIP_ARCHIVE_FILE_TYPE: 'Gzip compressed tar archive',
       PLAIN_TEXT_FILE_TYPE: 'Plain text file',
       PDF_DOCUMENT_FILE_TYPE: 'PDF document',
       WORD_DOCUMENT_FILE_TYPE: 'Word document',
       POWERPOINT_PRESENTATION_FILE_TYPE: 'PowerPoint presentation',
       EXCEL_FILE_TYPE: 'Excel spreadsheet',
 
-      SEARCH_NO_MATCHING_FILES: 'No files match <b>"$1"</b>'
+      SEARCH_NO_MATCHING_FILES: 'No files match <b>"$1"</b>',
+
+      TIME_TODAY: 'Today $1',
+      TIME_YESTERDAY: 'Yesterday $1'
     });
   }
 };
 
 /**
  * Mock object for |chrome.extension|.
  */
 chrome.extension = {
   /**
    * @param {string} path Extension-relative path.
@@ skipping 88 matching lines @@
 
   setWindowHeight: function(height) {
     this.popup_.style.height = height + 'px';
   },
 
   closeWindow: function() {
     this.popup_.parentNode.removeChild(this.popup_);
     this.popup_ = null;
   }
 };
+
+/**
+ * TODO(olege): Remove once a Chrome with this interface available is released.
+ */
+var v8Intl = (function() {
+
+var v8Intl = {};
+
+/**
+ * Constructs v8Intl.DateTimeFormat object given optional locales and options
+ * parameters.
+ *
+ * @constructor
+ * @param {Array?} locales Unused in the mock.
+ * @param {Object} options Unused in the mock.
+ */
+v8Intl.DateTimeFormat = function(locales, options) {
+  return {
+    format: function(dateValue) {
+      return dateValue.toString();
+    }
+  };
+};
+
+return v8Intl;
+}());