[ChromeVox] Remove old developer logging

This change should have no impact on user experience.

R=akihiroota

AX-Relnotes: n/a.
Bug: none
Test: cq
Change-Id: Id5fd8e476a494828c197c8c068a707812dd9966e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3876946


Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
Auto-Submit: Anastasia Helfinstein <anastasi@google.com>
Cr-Commit-Position: refs/heads/main@{#1044791}