GitLab

This cl add a STOP button to timer notification.

Bug: b/118655426
Test: manual
Change-Id: I88752010e4b0c5be54debddb8394827a798d65fe
Reviewed-on: https://chromium-review.googlesource.com/c/1330296Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Tao Wu <wutao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607007}