Add Visual Viewport to GroupData (#1394)
Add Visual Viewport to GroupData (#1394)

This patch adds a record for the Visual Viewport API to the
GroupData.json file. This is based on the following spec
draft:

https://wicg.github.io/visual-viewport/#the-visualviewport-interface

We already document this API.
jpmedley/kumascript,jpmedley/kumascript