Hotword Audio Verification App: Adds to hotwordPrivate API

chrome/common/extensions/api/_permission_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 permissions for 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.
 
 // To add a new whitelisted ID, SHA-1 it and force it to uppercase. In Bash:
@@ skipping 490 matching lines @@
     "extension_types": [
       "extension", "legacy_packaged_app", "hosted_app", "platform_app"
     ]
   },
   "history": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app"]
   },
   "hotwordPrivate": {
     "channel": "stable",
-    "extension_types": ["extension"],
+    "extension_types": ["extension", "platform_app"],
     "whitelist": [
       "8CE39F175D076AD6BDF7CBF418F2409558B367E3",  // hotword_helper
-      "09FDCB5851B8F3378DB630D06E316076E89C95A6"   // hotword nacl
+      "09FDCB5851B8F3378DB630D06E316076E89C95A6",  // hotword nacl
+      "B6356EFF4047BC5F868C7D91868B6F5C01951A8A"   // hotword_audio_verification
     ]
   },
   "identity": {
     "channel": "stable",
     "extension_types": ["extension", "platform_app"]
   },
   "identity.email": {
     "channel": "stable",
     "extension_types": ["extension", "platform_app"]
   },
@@ skipping 535 matching lines @@
   },
   "webRequest": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app"]
   },
   "webRequestBlocking": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app"]
   }
 }