Implement an initial extension settings API.

chrome/renderer/resources/renderer_extension_bindings.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.
 
 // This script contains unprivileged javascript APIs related to chrome
 // extensions.  It is loaded by any extension-related context, such as content
 // scripts or toolstrips.
 // See user_script_slave.cc for script that is loaded by content scripts only.
 // TODO(mpcomplete): we also load this in regular web pages, but don't need to.
 
@@ skipping 293 matching lines @@
       "experimental.app",
       "experimental.bookmarkManager",
       "experimental.contentSettings",
       "experimental.debugger",
       "experimental.extension",
       "experimental.infobars",
       "experimental.input",
       "experimental.inputUI",
       "experimental.metrics",
       "experimental.permissions",
+      "experimental.settings",
       "experimental.popup",
       "experimental.processes",
       "experimental.rlz",
       "experimental.sidebar",
       "experimental.webNavigation",
       "experimental.webRequest",
       "fileBrowserHandler",
       "fileBrowserPrivate",
       "fileSystem",
       "history",
@@ skipping 26 matching lines @@
       "extension.onRequestExternal",
       "extension.setUpdateUrlData",
       "i18n.getAcceptLanguages"
     ];
     for (var i = 0; i < privileged.length; i++) {
       createStub(privileged[i]);
     }
   }
 
 })();