Remove experimental permission from infobars API and moving it to dev channel

chrome/test/webdriver/test/infobar_browser_action_extension/bg.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.
 
 var g_infobarReady = false;
 var g_callback = null;
 function waitForInfobar(callback) {
   if (g_infobarReady)
     callback();
   g_callback = callback;
 }
 
 chrome.tabs.getSelected(null, function(tab) {
-  chrome.experimental.infobars.show(
+  chrome.infobars.show(
       {'tabId': tab.id, 'path': 'view_checks.html'}, function() {
     g_infobarReady = true;
     if (g_callback)
       g_callback();
   });
 });