Ensure that the bubble has been laid out before adjusting its position

When adjusting bubble position at first time, its size was empty because
it had not yet completed the layout, resulting in incorrect bubble
position. This CL ensures that the bubble has been laid out before
adjusting its position.

Bug: 447171226
Change-Id: I83ae0263206d6bcf9f4958549a1f3eda7a2dc8df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7011027
Reviewed-by: Joey Arhar <jarhar@chromium.org>
Commit-Queue: Perry <perryuwang@gmail.com>
Cr-Commit-Position: refs/heads/main@{#1527934}