This is a variation on bc3e8a9963cf9a64d114ec751c875025af169690, which was reverted due to issues on iOS. Safari's "in response to user action" check cannot follow the `runAfterFramePaint` chain of interaction -> requestAnimationFrame -> messageChannel, and so some sensitive browser APIs (e.g. clipboard, upload, etc.) were blocked.
This commit is similar, but uses `next()` instead of `runAfterFramePaint()`. The result seems the same, but doesn't have the same issue on iOS.
The chat-emoji-picker change was required to resolve a test failure. The emoji picker has never closed-on-scroll on desktop, so there is no user-facing change in behavior.
dfc947a97d