Remove unused Calculate predicted seconds to photons from now for tracked device poses Update HMD transform in various additional places, should help with latency Fast path specifically for *hmd* pose retrieval, should help a tiny bit with latency VRSystem.Update refactor Shorten GetPredictedSecondsToPhotonsFromNow to GetPredictedTime, use GetDeviceToAbsoluteTrackingPose for GetHmdMatrix