Add ability to limit when context menu items appear with url patterns....

chrome/test/data/extensions/context_menus/test.js

-// Copyright (c) 2010 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.
-
-// Checks that there is only one window and one tab, and calls back |callback|
-// with its id (or -1 if there is more than 1 window or more than 1 tab).
-function getCurrentSingleTabId(callback) {
-  chrome.windows.getAll({"populate":true}, function(windows) {
-    if (windows.length != 1 || windows[0].tabs.length != 1) {
-      callback(-1);
-    } else {
-      callback(windows[0].tabs[0].id);
-    }
-  });
-}
-
-function navigateCurrentTab(url) {
-  getCurrentSingleTabId(function(tabid) {
-    chrome.tabs.update(tabid, {"url": url});
-  });
-}
-
-function onclick(info) {
-  navigateCurrentTab(chrome.extension.getURL("test2.html"));
-}
-
-window.onload = function() {
-  chrome.contextMenus.create({"title":"Extension Item 1",
-                              "onclick": onclick}, function() {
-    if (!chrome.extension.lastError) {
-      navigateCurrentTab(chrome.extension.getURL("test.html"));
-    }
-  });
-};