Use common generated file for inputMethodPrivate APIs.

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",
@@ skipping 204 matching lines @@
             "description": "List of removed words.",
             "items": {
               "type": "string"
             }
           }
         ]
       }
     ]
   }
 ]