Steps to reproduce:
1. Download and open the attached project
2. Build and run for WebGL
3. Press and hold any of the arrow keys
4. Click away somewhere outside the game window, but in the same browser window

Expected result: focus loss is registered, input is reset
Actual result: focus is not registered and the input axis value stays at what it was before clicking off

Reproduced on 2017.4.0f1, 2017.4.21f1, 2018.3.7f1, 2019.1.0b4, 2019.2.0a6

Notes: it also does not instantly reset input upon refocusing the game view