Enable WebVR origin trial experiments.

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

 // 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.
 
 enum VREye {
     "left",
     "right"
 };
 
 // http://mozvr.github.io/webvr-spec/webvr.html#vrdisplay
 [
-    RuntimeEnabled=WebVR
+    OriginTrialEnabled=WebVR
 ] interface VRDisplay {
     // An identifier for this device unique across VRDisplays.
     readonly attribute unsigned long displayId;
 
     // A user-readable name identifying the device.
     readonly attribute DOMString displayName;
 
     readonly attribute boolean isConnected;
     readonly attribute boolean isPresenting;
 
@@ skipping 23 matching lines @@
 
     // Get the sources currently being presented.
     sequence<VRLayer> getLayers();
 
     // The VRLayer provided to the `VRDisplay` will be captured and presented
     // in the HMD. Calling this function has the same effect on the source
     // canvas as any other operation that uses its source image, and canvases
     // created without preserveDrawingBuffer set to true will be cleared.
     void submitFrame();
 };