Prevent browser crash resulting from misbehaving WebVR renderer requesting multiple VSyncs.

third_party/WebKit/LayoutTests/vr/resources/mock-vr-service.js

 'use strict';
 
 let mockVRService = loadMojoModules(
     'mockVRService',
     ['mojo/public/js/bindings',
      'device/vr/vr_service.mojom',
     ]).then(mojo => {
   let [bindings, vr_service] = mojo.modules;
 
   class MockVRDisplay {
@@ skipping 58 matching lines @@
       if (this.pose_) {
         this.pose_.timestamp = this.timeDelta_;
         this.pose_.poseIndex++;
       }
 
       let retval = Promise.resolve({
         pose: this.pose_,
         time: {
           microseconds: this.timeDelta_,
         },
+        frameId: 0,
+        error: vr_service.VRVSyncProvider.Status.SUCCESS,
       });
 
       this.timeDelta_ += 1000.0 / 60.0;
       return retval;
     }
     initPose() {
       this.pose_ = {
         timestamp: 0,
         orientation: null,
         position: null,
@@ skipping 57 matching lines @@
   return new MockVRService(mojo.frameInterfaces);
 });
 
 function vr_test(func, vrDisplays, name, properties) {
   mockVRService.then( (service) => {
     service.setVRDisplays(vrDisplays);
     let t = async_test(name, properties);
     func(t, service);
   });
 }