[mahi] fix mess caused by question from context menu

Question sent from context menu may be messy when the user also switches
tabs.
This is a fix to this issue.

Fixed: b:332622473
Test: autoninja -C out_${SDK_BOARD}/Release chrome
Change-Id: Ief5ded649c21c2ab5fa7172b011151f26fbc72d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5417755


Commit-Queue: Xinglong Luan <alanlxl@chromium.org>
Commit-Queue: Thanh Nguyen <thanhdng@chromium.org>
Reviewed-by: Thanh Nguyen <thanhdng@chromium.org>
Auto-Submit: Xinglong Luan <alanlxl@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1281670}