- Set `document.scrollingElement` as the scrolling element
for scrolling to anchors when the app is mobile mode
to enhance support in newer browsers.
The CSS View Module spec considers `document.documentElement`/`<html>`
to be the standard scrolling element
and that is what appears to be used in the latest Firefox and Chrome.
However, some older browsers and even the current Safari
use `document.body` as the scrolling element
which is why I suspect the original code used `document.body`.
Since some browsers scroll on different elements,
`document.scrollingElement` exists
so the browser can tell us what to use
for scrolling to anchors work for all modern browsers.
Since `document.scrollingElement` is undefined in older browsers,
`document.body` is available as fallback mobile scrolling element.
Grant Bourque
d657377d1c