Make [TypeChecking=Interface] the default

third_party/WebKit/Source/modules/vr/HMDVRDevice.idl

 // Copyright 2015 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.
 
 enum VREye {
     "left",
     "right"
 };
 
 // An HMDVRDevice represents a Head Mounted Display. The interface provides all
 // the information necessary to correctly render a stereo 3D scene for a given
 // headset.
 // http://mozvr.github.io/webvr-spec/webvr.html#hmdvrdevice
 [
     RuntimeEnabled=WebVR,
-    TypeChecking=Interface
 ] interface HMDVRDevice : VRDevice {
     VREyeParameters getEyeParameters(VREye whichEye);
     void setFieldOfView(optional VRFieldOfView leftFov, optional VRFieldOfView rightFov);
 };