Add chrome.inputMethodPrivate.onImeMenuActivationChanged API.

chrome/test/data/extensions/api_test/input_method/ime_menu/background.js

+// Copyright 2016 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.
+
+function imeMenuConfigTest() {
+  chrome.inputMethodPrivate.getInputMethodConfig(function(config) {
+    chrome.test.assertTrue(config["isImeMenuActivated"]);
+    chrome.test.succeed();
+  });
+}
+
+function imeMenuActivationChangedTest() {
+  chrome.inputMethodPrivate.onImeMenuActivationChanged.addListener(
+      function(isActive) {
+    chrome.test.assertFalse(isActive);
+    // Wait for the 'event_ready' message in
+    // ExtensionInputMethodApiTest.ImeMenuActivation.
+    chrome.test.sendMessage('event_ready');
+  });
+  // We just add the listener without receiving any event at first time.
+  // The test continues in input_method_apitest_chromeos.cc to trigger
+  // the event, and succeeds after getting the 'event_ready' message.
+  chrome.test.succeed();
+}
+
+chrome.test.sendMessage('config_ready');
+chrome.test.runTests(

[Devlin, 2016/01/25 20:35:36]

This style of test would be more suited to just the sendMessage style, rather
than using runTests() at all.  So let's remove this (and all the
chrome.test.succeeds()) and only use chrome.test.sendMessage to indicate when
something should/did happen.

[Azure Wei, 2016/01/27 05:06:26]

Done.

+    [imeMenuConfigTest, imeMenuActivationChangedTest]);