…itch on child window removal"

This reverts commit 50361d0485ffaac5fa504ad4c38a68c00e8344a0 (but leaves the test file
moving from browser_tests to interactive_ui_tests to reduce disruption)

Also reverts 3b927a9dbb080ca137fd8da0a45acad2cf4ae554 which depends
on this.

(cherry picked from commit fae31a511ab4e049793131bc277413378d59dda7)

Bug: 1492984
Change-Id: I1aff7e38a374c8db61bf59a2ad62578747000702
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4960653
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Leonard Grey <lgrey@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Keren Zhu <kerenzhu@chromium.org>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Cr-Original-Commit-Position: refs/heads/main@{#1212948}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4966202
Reviewed-by: Daniel Yip <danielyip@google.com>
Owners-Override: Daniel Yip <danielyip@google.com>
Cr-Commit-Position: refs/branch-heads/5993@{#1402}
Cr-Branched-From: 511350718e646be62331ae9d7213d10ec320d514-refs/heads/main@{#1192594}