Diff of WebXR

• The added line is THIS COLOR.
• The deleted line is THIS COLOR.
• Go to WebXR.

- 2019-09-06 CEDEC 2019 Day 3 WebXRの現状と実社会への応用事例 / Talk about WebXR at CEDEC 2019
-- https://speakerdeck.com/ikkou/talk-about-webxr-at-cedec-2019