Chrome Version: 55.0.2883.87 (Official Build) (64-bit)chrome://version)
OS: Linux, OS X

What steps will reproduce the problem?
(1) Visit https://jsfiddle.net/api/mdn/US/docs/Web/Events/blur
(2) Click on either the "text input" or "password" fields. Note that it turns pink
(3) Open a second window.
(4) Press Alt (Cmd on Mac) + Tab and hold.

What is the expected result?
The OS should display the list of windows, and the text entry field should turn white, indicating that Chrome has generated a blur event because it no longer has input focus.

What happens instead?
On Windows and ChromeOS, it behaves as expected. On Mac and Linux (possibly dependent on the window manager), the entry stays pink until a different window is selected.

Why this matters:
Similar to bug 424322 (Missing keyup events when using Mission Control), applications like Chrome Remote Desktop rely on receiving keyup events to track the local keyboard state. Failing that, they rely on blur events to indicate that any keys currently pressed might be released while input focus is elsewhere (Chrome Remote Desktop responds by releasing all keys, for example). Absent either of these events, the user is left with a stuck key, which can be very jarring.