Make [TypeChecking=Interface] the default

third_party/WebKit/Source/core/events/UIEvent.idl

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 10 matching lines @@
 
 [
     Constructor(DOMString type, optional UIEventInit eventInitDict)
 ] interface UIEvent : Event {
     readonly attribute Window? view;
     readonly attribute long detail;
     [RuntimeEnabled=InputDeviceCapabilities] readonly attribute InputDeviceCapabilities? sourceCapabilities;
 
     // https://w3c.github.io/uievents/#idl-interface-UIEvent-initializers
     // TODO(philipj): None of the initUIEvent() arguments should be optional.
-    [Measure] void initUIEvent([Default=Undefined] optional DOMString type,
-                               [Default=Undefined] optional boolean bubbles,
-                               [Default=Undefined] optional boolean cancelable,
-                               [Default=Undefined] optional Window? view,
-                               [Default=Undefined] optional long detail);
+    [Measure, LegacyInterfaceTypeChecking] void initUIEvent([Default=Undefined] optional DOMString type,
+                                                            [Default=Undefined] optional boolean bubbles,
+                                                            [Default=Undefined] optional boolean cancelable,
+                                                            [Default=Undefined] optional Window? view,
+                                                            [Default=Undefined] optional long detail);
 
     // FIXME: this belongs on the KeyboardEvent interface
     [MeasureAs=UIEventWhich] readonly attribute long which;
 };