Clean up WebVR RequestPresent and make callback asynchronous.

device/vr/vr_display_impl.cc

Index: device/vr/vr_display_impl.cc
diff --git a/device/vr/vr_display_impl.cc b/device/vr/vr_display_impl.cc
index bdbb073136f33bd921948c5902319f0fcd1f44ad..9c4b2c4960e98e5c7be7c2ed8c5515d33eb0f612 100644
--- a/device/vr/vr_display_impl.cc
+++ b/device/vr/vr_display_impl.cc
@@ -11,7 +11,10 @@
 namespace device {
 
 VRDisplayImpl::VRDisplayImpl(device::VRDevice* device, VRServiceImpl* service)
-    : binding_(this), device_(device), service_(service) {
+    : binding_(this),
+      device_(device),
+      service_(service),
+      weak_ptr_factory_(this) {
   mojom::VRDisplayInfoPtr display_info = device->GetVRDevice();
   // Client might be null in unittest.
   // TODO: setup a mock client in unittest too?
@@ -40,16 +43,24 @@ void VRDisplayImpl::ResetPose() {
   device_->ResetPose();
 }
 
-void VRDisplayImpl::RequestPresent(bool secureOrigin,
+void VRDisplayImpl::RequestPresent(bool secure_origin,
                                    const RequestPresentCallback& callback) {
   if (!device_->IsAccessAllowed(service_)) {

[bajones, 2016/11/16 21:44:17]

Realizing now that it's possible that multiple pages could requestPresent
simultaneously, and since vr_shell only handles one callback at a time that'll
leave one of them "stranded". Let's set a flag on device_ that indicates it's
got a pending requestPresent callback, clear the flag in RequestPresentResult,
and add a check for that flag to this if statement.

[mthiesse, 2016/11/16 21:57:53]

Probably cleaner if I handle this in vr_shell_delegate, and call the
callback.Run(false) if another callback is pending.

     callback.Run(false);
     return;
   }
 
-  bool success = device_->RequestPresent(secureOrigin);
+  device_->RequestPresent(base::Bind(&VRDisplayImpl::RequestPresentResult,
+                                     weak_ptr_factory_.GetWeakPtr(), callback,
+                                     secure_origin));
+}
+
+void VRDisplayImpl::RequestPresentResult(const RequestPresentCallback& callback,
+                                         bool secure_origin,
+                                         bool success) {
   if (success) {
     device_->SetPresentingService(service_);
+    device_->SetSecureOrigin(secure_origin);
   }
   callback.Run(success);
 }