Fix Search key incorrectly recognized as Alt by the keyboard overlay.

chrome/browser/resources/chromeos/keyboard_overlay.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.
 
 <include src="keyboard_overlay_data.js"/>
 <include src="keyboard_overlay_accessibility_helper.js"/>
 
 var BASE_KEYBOARD = {
   top: 0,
   left: 0,
@@ skipping 159 matching lines @@
  */
 function getModifiers(e) {
   if (!e)
     return [];
 
   var isKeyDown = (e.type == 'keydown');
   var keyCodeToModifier = {
     16: 'SHIFT',
     17: 'CTRL',
     18: 'ALT',
-    91: 'ALT', // left ALT pressed with SHIFT
-    92: 'ALT', // right ALT pressed with SHIFT
   };
   var modifierWithKeyCode = keyCodeToModifier[e.keyCode];
   var isPressed = {'SHIFT': e.shiftKey, 'CTRL': e.ctrlKey, 'ALT': e.altKey};
   // if e.keyCode is one of Shift, Ctrl and Alt, isPressed should
   // be changed because the key currently pressed
   // does not affect the values of e.shiftKey, e.ctrlKey and e.altKey
   if (modifierWithKeyCode)
     isPressed[modifierWithKeyCode] = isKeyDown;
 
   // make the result array
@@ skipping 409 matching lines @@
  * Handles click events of the learn more link.
  * @param {Event} e Mouse click event.
  */
 function learnMoreClicked(e) {
   chrome.send('openLearnMorePage');
   chrome.send('DialogClose');
   e.preventDefault();
 }
 
 document.addEventListener('DOMContentLoaded', init);