Remove enable-accessibility-tab-switcher from chrome://flags

Leaving the swich in place as it is highly used as a command line value,
but removing it to trim down chrome://flags size.

BUG=961861

Change-Id: I0d664bc1888de5ffd0377ebb7f27d37d36be59a3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1625393
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662381}
4 files changed