Use OnceCallback on Mojo interfaces in //chrome/common/extensions

chrome/common/extensions/BUILD.gn

 # Copyright 2016 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.
 
 import("//build/config/features.gni")
 import("//extensions/features/features.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//tools/json_schema_compiler/json_features.gni")
 
 assert(enable_extensions)
@@ skipping 18 matching lines @@
     "removable_storage_writer.mojom",
   ]
 
   if (is_win) {
     sources += [ "wifi_credentials_getter.mojom" ]
   }
 
   public_deps = [
     "//mojo/common:common_custom_types",
   ]
-
-  # TODO(crbug.com/714018): Convert the implementation to use OnceCallback.
-  use_once_callback = false
 }