Revert of ozone: xkb: Load keymaps on worker thread & cache them (patchset #17 id:310001 of https://codereview.chromium.org/
817983002/)
Reason for revert:
Adds thread-unsafe code.
Original issue's description:
> ozone: xkb: Load keymaps on worker thread & cache them
>
> 1. Free xkb keymaps in the destructor.
> 2. Moves kemap load into another worker thread.
> 3. Adds keymap caching.
>
> BUG=430194
>
> Committed: https://crrev.com/
f0b38f78f146cedf336ac9ad0236f681833c7263
> Cr-Commit-Position: refs/heads/master@{#309928}
TBR=shuchen@chromium.org,kpschoedel@chromium.org,fengyuan@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=430194
Review URL: https://codereview.chromium.org/
823633003
Cr-Commit-Position: refs/heads/master@{#310105}