[Extensions] Simplify Extension Keybinding API Tests

chrome/test/data/extensions/api_test/keybinding/basics/background.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.
 
 // Called when the user clicks on the browser action.
 chrome.browserAction.onClicked.addListener(function(windowId) {
-  chrome.tabs.executeScript(null, { code: "document.body.bgColor='red'" });
+  chrome.test.sendMessage('basics browser action');
 });
 
 // Called when the user activates the command.
 chrome.commands.onCommand.addListener(function(command) {
-  chrome.tabs.executeScript(null, { code: "document.body.bgColor='blue'" });
+  chrome.test.sendMessage('basics command');

[Finnur, 2015/01/29 09:38:39]

nit: I would probably have sent the contents of command, because it can differ
based on what key is pressed. (I know there's only one such command in this
extension, but code tends to get copied around).

[Devlin, 2015/01/30 17:21:44]

Done.

 });
 
 chrome.test.notifyPass();