Add chrome.inputMethodPrivate.onImeMenuActivationChanged API.

chrome/common/extensions/api/input_method_private.json

 // 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.
 
 [
   {
     "namespace": "inputMethodPrivate",
     "compiler_options": {
       "implemented_in": "chrome/browser/chromeos/extensions/input_method_api.h"
     },
     "description": "none",
     "functions": [
       {
         "name": "getInputMethodConfig",
         "type": "function",
         "description": "Gets configurations for input methods.",
         "parameters": [
           {
             "name": "callback",
             "type": "function",
             "optional": false,
             "description": "Callback which is called with the config object.",
             "parameters": [
               {
                 "name": "config",
                 "type": "object",
                 "description": "The input method config object.",
                 "properties": {
-                  "isPhysicalKeyboardAutocorrectEnabled": {"type": "boolean"}
+                  "isPhysicalKeyboardAutocorrectEnabled": {"type": "boolean"},
+                  "isImeMenuActivated": {"type": "boolean"}
                 }
               }
             ]
           }
         ]
       }, {
         "name": "getInputMethods",
         "type": "function",
         "description": "Gets all whitelisted input methods.",
         "parameters": [
@@ skipping 199 matching lines @@
             }
           }, {
             "name": "removed",
             "type": "array",
             "description": "List of removed words.",
             "items": {
               "type": "string"
             }
           }
         ]
+      }, {
+        "name": "onImeMenuActivationChanged",
+        "type": "function",
+        "description": "Fired when the IME menu is activated or deactivated.",
+        "parameters": [
+          {
+            "name": "activation",
+            "type": "boolean",
+            "description": "Whether the IME menu is currently active."
+          }
+        ]
       }
     ]
   }
 ]