GitLab

changes:
Decouples `show notification` from OnAccessibilityStatusChanged.
Callers decide to whether to show notification by explicitly notifying
observer themselves.

Bug: none
Test: tested on emulator, everything looks fine
Change-Id: If5cfbeaabea2583f7fe558cf098b69446a63bb14
Reviewed-on: https://chromium-review.googlesource.com/976091
Commit-Queue: Qiang Xu <warx@google.com>
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545881}