Adds the input method private API to allow the component IME extension to change the XKB layout.

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"
     },
@@ skipping 140 matching lines @@
             "parameters": [
               {
                 "name": "enabled",
                 "type": "boolean",
                 "optional": false,
                 "description": "The result of whether enabled."
               }
             ]
           }
         ]
+      }, {
+        "name": "setXkbLayout",
+        "type": "function",
+        "description": "Sets the XKB layout for the given input method.",
+        "parameters": [
+          {
+            "name": "xkb_name",
+            "type": "string",
+            "description": "The XKB layout name."
+          },
+          {
+            "name": "callback",
+            "type": "function",
+            "optional": true,
+            "description": "Callback which is called when the layout is set.",
+            "parameters": []
+          }
+        ]
       }
     ],
     "events": [
       {
         "name": "onChanged",
         "type": "function",
         "description": "Fired when the input method is changed.",
         "parameters": [
           {
             "name": "newInputMethodId",
@@ skipping 54 matching lines @@
             "description": "List of removed words.",
             "items": {
               "type": "string"
             }
           }
         ]
       }
     ]
   }
 ]