Mobile chipsets can barely support 1080p 2D 60FPS.
You want to support >1080p 3D graphics projected onto the real world with VERY harsh latency limits (human sensory). Modern GPU's that eat more than 100watts and have terraflops of compute power are only starting to offer the compute speeds VR needs.
With Moore's Law ending I don't see mobile ever being able to render VR settings to a sufficient degree.