Canvas resize during morph not behaving as expected

In any full-window Cesium app that has a 2D/3D switcher:

1) start windowed
2) switch to 2D
3) switch back to 3D, but during the morph go fullscreen (F11 on Windows works well)

Reproduce this in a full-window Cesium app using the listed sequence: start windowed, switch to 2D, switch back to 3D, and enter fullscreen during the morph. Compare canvas sizing before, during, and after the transition; done means resizing remains correct when fullscreen is entered during the 2D-to-3D morph.

Written by the indexing model from the issue text.