Having two Game view windows, only one Game view window receives input. If selecting the other one, input is not received.

Reproducible on 5.1, 5.2, 5.3, 5.4 versions.

Repro steps:
1. open "GameViewTest.zip". Project should have two Game view windows. If not set, add new tab for second Game view window.
2. open test scene "Scene".
3. press play. By pressing keyboard key "A" try to switch focus between one window and the other one. While pressing "A", console should print debug messages using both windows, but it works only with one window.
Also, observe, that Input.mousePosition is not correct on the second Game view window.

Expected: mouse position should be identical on both views, focusing between Game view windows input should always be received.