Update NCP for 115.10.0

This patch simply makes some slight changes to the scrollbar calculation
code. In short, it:

- Shows horizontal scrollbar buttons on frames with thin scrollbar CSS
  styles. This was broken in the native theme due to an oversight.
- Attempts to fix a bug with the Windows eXPerience R2 visual style by
  vaporvance, but this did not end up working. Vertical scrollbar buttons
  are still too tall for the scrollbar frame, and I don't know why. It does
  not occur with any other visual style that I'm aware of, nor does it
  occur in the classic theme.

Signed-off-by: Isabella <[email protected]>