Whitelist the fileSystem.write API for an internally developed extension

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.
 
 {
   "activeTab": {
     "channel": "stable",
     "extension_types": ["extension", "packaged_app"],
     "min_manifest_version": 2
   },
@@ skipping 149 matching lines @@
   },
   "fileBrowserHandler": {
     "channel": "stable",
     "extension_types": ["extension", "packaged_app", "platform_app"]
   },
   "fileBrowserPrivate": {
     "channel": "stable",
     "extension_types": ["extension", "packaged_app"],
     "location": "component"
   },
-  "fileSystem": {
+  "fileSystem": [{
     "channel": "stable",
     "extension_types": ["platform_app"]
-  },
-  "fileSystem.write": {
+  },{
+    "channel": "stable",
+    "extension_types": ["extension"],
+    "whitelist": [ "2FC374607C2DF285634B67C64A2E356C607091C3" ]
+  }],
+  "fileSystem.write": [{
     "channel": "stable",
     "extension_types": ["platform_app"]
-  },
+  },{
+    "channel": "stable",
+    "extension_types": ["extension"],
+    "whitelist": [ "2FC374607C2DF285634B67C64A2E356C607091C3" ]
+  }],
   "fontSettings": {
     "channel": "stable",
     "extension_types": ["extension", "packaged_app"]
   },
   "fullscreen": {
     "channel": "stable",
     "extension_types": ["platform_app"]
   },
   "geolocation": {
     "channel": "stable",
@@ skipping 312 matching lines @@
   },
   "webRequestBlocking": {
     "channel": "stable",
     "extension_types": ["extension", "packaged_app"]
   },
   "webview": {
     "channel": "stable",
     "extension_types": ["platform_app"]
   }
 }