Updates SupportsMouseFocus to respect SupportsFocus.

Before we just checked if we were in fullscreen, but we should also check
if we even support foucs in the first place.

Bug: 943575
Change-Id: I0bd6d0c74c3b6178085aa2c4732f83f6891066d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1532907
Commit-Queue: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642926}
2 files changed