Revert of Track the active ExtensionKeybindingRegistry and make it available to EventRewriter.

chrome/test/data/extensions/api_test/keybinding/chromeos_conversions/background.js

-// Copyright 2014 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.
-
-// A list of all commands sorted in expected order.
-var expectedCommands = [
-  'Search-Shift-Left',
-  'Search-Shift-Up',
-  'Search-Shift-Right',
-  'Search-Shift-Down'
-];
-
-chrome.commands.onCommand.addListener(function (command) {
-  if (expectedCommands[0] != command)
-    chrome.test.notifyFail('Unexpected command: ' + command);
-  expectedCommands.splice(0, 1);
-  if (expectedCommands.length == 0)
-    chrome.test.notifyPass();
-});
-
-chrome.test.notifyPass();