If Atom isn't initialized and able to produce a ViewportContext, the Editor would crash. This attempts to make the initialization fail a bit more gracefully and fixes the crash in the cases I've tested.
-Implements ResetInputChannels for ViewportController API and SetEnabled for ViewportControllerList
-Disables all viewport controllers while in game mode
grabKeyboard was used by CRenderViewport to ensure it received some events, but that logic is no longer needed and the corresponding release was removed. This just removes grabKeyboard entirely - eventually all input event logic will be removed as well.
nvsickle
Chris Galvan
Alex Peterson
alexpete