Allow component IME extension use app.window and add 'ime' window type for app window

chrome/common/extensions/api/_api_features.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.
 
 // This features file defines extension APIs implemented under src/chrome.
 // See extensions/common/features/* to understand this file, in particular
 // feature.h, simple_feature.h, and base_feature_provider.h.
 //
 // Note that specifying "web_page", "blessed_web_page", or "all" as a context
 // type will require manually updating chrome/renderer/resources/dispatcher.cc.
@@ skipping 24 matching lines @@
     "contexts": ["blessed_extension"]
   },
   "alarms": {
     "dependencies": ["permission:alarms"],
     "contexts": ["blessed_extension"]
   },
   "app": {
     "blacklist": [
       "2FC374607C2DF285634B67C64A2E356C607091C3",  // Quickoffice
       "3727DD3E564B6055387425027AD74C58784ACC15",  // Quickoffice internal
-      "12E618C3C6E97495AAECF2AC12DEB082353241C6"   // QO component extension
+      "12E618C3C6E97495AAECF2AC12DEB082353241C6",  // QO component extension
+      "06BE211D5F014BAB34BC22D9DDA09C63A81D828E",  // Official xkb extension
+      "F94EE6AB36D6C6588670B2B01EB65212D9C64E33"   // Open source xkb extension
     ],
     "channel": "stable",
     "extension_types": ["hosted_app", "extension", "legacy_packaged_app"],
     "contexts": [
       "blessed_extension",
       "unblessed_extension",
       "content_script",
       "web_page",
       "blessed_web_page"
     ],
@@ skipping 722 matching lines @@
     "internal": true,
     "channel": "stable",
     "dependencies": ["permission:webview"],
     "contexts": ["blessed_extension"]
   },
   "windows": {
     "dependencies": ["api:tabs"],
     "contexts": ["blessed_extension"]
   }
 }