Chrome Version: 69.0.3496.0 (but been happening regularly for *many* milestones)
OS: Win10

What steps will reproduce the problem?
(1) Have a window that has a side-effect, e.g. opens tooltips, when moused over (e.g. Hangouts)
(2) Use Chrome for a *while*

What is the expected result?
Hangouts window always gets MouseLeave event when interacting with another window (i.e. it no longer has mouse on it).

What happens instead?
Every now and then (multiple times a day but hard to repro at will) I get a sticky tooltip from the Hangout window painted over my foreground window. The only way to make it go away is to bring Hangouts back to foreground and mouse over it. Tooltips being driven by Blink, this isn't Hangouts specific, it just happens to be the way I most frequently experience this issue.

This has been a daily annoyance for me for a while, finally took some time to capture and report it :)

See video attached.
 

Deleted: Flakily missing MouseLeave signal.mp4 3.0 MB

	Flakily missing MouseLeave signal.mp4 3.0 MB View Download