Add chrome.inputMethodPrivate.onImeMenuActivationChanged API.

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

 // Copyright (c) 2011 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 kNewInputMethodTemplate = '_comp_ime_{EXT_ID}xkb:fr::fra';
 var kInitialInputMethodRegex = /_comp_ime_([a-z]{32})xkb:us::eng/;
 var kInvalidInputMethod = 'xx::xxx';
 
 var testParams = {
   initialInputMethod: '',
@@ skipping 174 matching lines @@
               chrome.test.assertTrue(removed.length === 0);
               chrome.test.assertEq(added[0], wordToAdd);
               chrome.test.succeed();
             });
       })
       .then(function() {
         return getAddPromise(wordToAdd);
       });
 }
 
+function imeMenuConfigTest() {
+  chrome.inputMethodPrivate.getInputMethodConfig(function(config) {
+    chrome.test.assertTrue(config["isImeMenuActivated"]);
+    chrome.test.succeed();
+  });
+}
+
+function imeMenuActivationChangedTest() {

[Devlin, 2016/01/21 19:36:02]

Thinking about this more, let's have this one be a separate browser test. 
Ideally, we have two types of extension API tests - those that use
chrome.test.runTests() and are entirely in the JS (possibly with a bit of set
up) and those that do back-and-forth communication using
chrome.test.sendMessage().  Overloading the two is a little bit of a pain,
especially because we might in the future want to do cleanup after runTests()
finishes, like removing all event listeners, and because having this event
listener here could affect future tests added to runTests() if they change the
activation.

[Azure Wei, 2016/01/23 02:40:39]

Done. The imeMenuConfigTest() and imeMenuActivationChangedTest() are moved to
make a new browser test: ExtensionInputMethodApiTest.ImeMenuActivation. 

+  chrome.inputMethodPrivate.onImeMenuActivationChanged.addListener(
+      function(activation) {

[Devlin, 2016/01/21 19:30:25]

nit: as elsewhere, prefer a variable name of "isActive" rather than "activation"
(which could be anything).

[Azure Wei, 2016/01/23 02:40:39]

Done.

+    chrome.test.assertTrue(!activation);

[Devlin, 2016/01/21 19:30:25]

prefer assertFalse

[Azure Wei, 2016/01/23 02:40:39]

Done.

+    chrome.test.sendMessage('ime_menu_ready');
+    chrome.test.succeed();

[stevenjb, 2016/01/21 19:16:16]

Remove this extra test.succeed() call and add a comment stating that we wait for
the 'ime_menu_ready' message in xtensionInputMethodApiTest.

[Azure Wei, 2016/01/23 02:40:39]

Done.

+  });
+  // We just add the listener without receiving any event at first.

[Devlin, 2016/01/21 19:30:25]

Add that the test is continued in the C++; otherwise it's unclear how this will
work.

[Azure Wei, 2016/01/23 02:40:39]

Done.

+  chrome.test.succeed();
+}
+
 chrome.test.sendMessage('ready');
 chrome.test.runTests(
     [initTests, setTest, getTest, observeTest, setInvalidTest, getListTest,
      loadDictionaryAsyncTest, fetchDictionaryTest, addWordToDictionaryTest,
-     dictionaryChangedTest]);
+     dictionaryChangedTest, imeMenuConfigTest, imeMenuActivationChangedTest]);