Methods and attributes being removed from Chrome 59's WebVR 1.1 implementation

Hi all!

Wanted to give a heads up that in Chrome 59 (which branched today and
should be hitting Beta channel in a couple of weeks) the WebVR
implementation (still the 1.1 API) will have several methods and attributes
removed. Specifically:

- VRDisplay.getPose()
- VRDisplay.resetPose()
- VRDisplay.isConnected
- VRDisplayCapabilities.hasOrientation
- VREyeParameters.fieldOfView

These have also been marked as "deprecated" in the WebVR 1.1 spec.
They were removed because no equivalent functionality is planned for
WebVR 2.0 and we want to ween WebVR apps off of them now so that the
eventual migration to 2.0 will be smoother.

You can see the associated bug, with links to the code change, here:
https://bugs.chromium.org/p/chromium/issues/detail?id=706561

Thanks!
--Brandon