Revert 260147 "Handling LevelDB errors encountered after open."

trunk/src/content/test/data/indexeddb/common.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 debug(message)
 {
   var span = document.createElement("span");
   span.appendChild(document.createTextNode(message));
   span.appendChild(document.createElement("br"));
   document.getElementById('status').appendChild(span);
@@ skipping 129 matching lines @@
   deleteRequest.onblocked = unexpectedBlockedCallback;
   deleteRequest.onsuccess = function() {
     var openRequest = indexedDB.open(dbname);
     openRequest.onerror = unexpectedErrorCallback;
     openRequest.onupgradeneeded = upgradeCallback;
     openRequest.onblocked = unexpectedBlockedCallback;
     if (optionalOpenCallback)
       openRequest.onsuccess = optionalOpenCallback;
   };
 }
-
-if (typeof String.prototype.startsWith !== 'function') {
-  String.prototype.startsWith = function (str) {
-    return this.indexOf(str) === 0;
-  };
-}