WebVR: Defer GetVSync calls until the current frame is submitted.

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 {
     constructor(interfaceProvider, displayInfo, service) {
       this.bindingSet_ = new bindings.BindingSet(vr_service.VRDisplay);
       this.displayClient_ = new vr_service.VRDisplayClientPtr();
       this.displayInfo_ = displayInfo;
       this.service_ = service;
       this.vsync_provider_ = new MockVRVSyncProvider();
 
       interfaceProvider.addInterfaceOverrideForTesting(
           vr_service.VRDisplay.name,
           handle => this.bindingSet_.addBinding(this, handle));
 
       if (service.client_) {
         this.notifyClientOfDisplay();
       }
     }
 
-    requestPresent(secureOrigin) {
+    requestPresent(secureOrigin, submitFrameClient) {
+      // console.log("requestPresent");

[mthiesse, 2017/05/18 23:39:14]

nit: remove commented out log statements here and below.

[klausw, 2017/05/19 04:06:47]

Done.

+      this.submitFrameClient_ = submitFrameClient;
       return Promise.resolve({success: true});
     }
 
+    submitFrame(frameId, mailboxHolder) {
+      // console.log("submitFrame frameId=" + frameId);
+      this.submitFrameClient_.onSubmitFrameTransferred();
+      this.submitFrameClient_.onSubmitFrameRendered();
+    }
+
     setPose(pose) {
       if (pose == null) {
         this.vsync_provider_.pose_ = null;
       } else {
         this.vsync_provider_.initPose();
         this.vsync_provider_.fillPose(pose);
       }
     }
 
-    getVRVSyncProvider(request) { this.vsync_provider_.bind(request); }
+    getVRVSyncProvider(request) {
+      this.vsync_provider_.bind(request);
+    }
 
     forceActivate(reason) {
       this.displayClient_.onActivate(reason);
     }
 
     notifyClientOfDisplay() {
       let displayPtr = new vr_service.VRDisplayPtr();
       let request = bindings.makeRequest(displayPtr);
       let binding = new bindings.Binding(
           vr_service.VRDisplay,
           this, request);
       let clientRequest = bindings.makeRequest(this.displayClient_);
       this.service_.client_.onDisplayConnected(displayPtr, clientRequest,
           this.displayInfo_);
     }
   }
 
   class MockVRVSyncProvider {
     constructor() {
       this.timeDelta_ = 0;
       this.binding_ = new bindings.Binding(vr_service.VRVSyncProvider, this);
       this.pose_ = null;
     }
     bind(request) {
       this.binding_.close();
       this.binding_.bind(request);
     }
     getVSync() {
+      // console.log("getVSync timeDelta=" + this.timeDelta_);
       if (this.pose_) {
         this.pose_.poseIndex++;
       }
 
       let retval = Promise.resolve({
         pose: this.pose_,
         time: {
           microseconds: this.timeDelta_,
         },
         frameId: 0,
@@ skipping 67 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);
   });
 }