Revert "[A11yPerformance] Additional cleanups from AXMode refactorings"

This reverts commit c8adeceeff6ac0cbdee2d961e11a59c9e8989743.

Reason for revert:
Bug:409833861

Original change's description:
> [A11yPerformance] Additional cleanups from AXMode refactorings
>
> R=grt@chromium.org
>
> Bug: none
> Change-Id: Ie116bf5cf296a4c4d0059f64889a94b0e3f9cd56
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6444371
> Reviewed-by: Greg Thompson <grt@chromium.org>
> Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1445316}

Bug: none
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I5698cfa850fb07f1e9ab44a1767d4c1b780e60ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6448883
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Gang Wu <gangwu@chromium.org>
Owners-Override: Gang Wu <gangwu@chromium.org>
Reviewed-by: Xinyi Ji <xinyiji@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1445506}