Add a centralized mechanism for whitelisting access to extension permissions.

chrome/test/data/extensions/api_test/terminal/no_permission/test.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.
-
-var kPermissionError = "Extension does not have the permission to use this API";
-
-chrome.test.runTests([
-  function tryOpenExtension() {
-    chrome.terminalPrivate.openTerminalProcess("crosh",
-        chrome.test.callbackFail(kPermissionError));
-  },
-  function trySendInput() {
-    chrome.terminalPrivate.sendInput(1222, "some input",
-        chrome.test.callbackFail(kPermissionError));
-  },
-  function tryClose() {
-    chrome.terminalPrivate.closeTerminalProcess(1222,
-        chrome.test.callbackFail(kPermissionError));
-  }
-]);