merge_pr_50222

Add tasks for gain/lose interest on interesttarget [2/N]

This CL changes the behavior of gaining and losing interest such that
both are scheduled as tasks, optionally with CSS-driven delays. That
not only adds the native ability to control those delays (which, per
the conversation at [1], seems important) but also this resolves
some interesting behavior even when the delays are zero:

• position the popover on top of the interest invoker
• show interest, via hover, on the interest invoker
  --> that will invoke the target popover
• the target obscures the invoker, which immediately triggers the
  loss of interest on the invoker, and that closes the popover

Bug: 326681249
Change-Id: I88d1cdaf975d56b819a0ff93cc8a48c2c5d71649
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6175776
Reviewed-by: David Baron [email protected]
Commit-Queue: Mason Freed [email protected]
Auto-Submit: Mason Freed [email protected]
Cr-Commit-Position: refs/heads/main@{#1409860}