Simplify keyboard focus rule to just 'widget in front', full stop.

Source/Integration/PlayerControllerBase.h

@@ -65,10 +65,6 @@ public:
 	// FProperty so we always see the current value without caching it.
 	static class UInputComponent* GetWidgetInputComponent(class UUserWidget *Widget);
 
-	// Restore focus back to the window that is in front, if it wants focus.
-	UFUNCTION(BlueprintCallable, meta = (WorldContext = "Context"), Category = "Luprex|Root Canvas")
-	static void RestoreFocusToFrontWidget(const UObject *Context);
-
 	// Add a widget to the root canvas at ZOrder 0 with default slot flags.
 	UFUNCTION(BlueprintCallable, Category = "Luprex|Root Canvas",
 		meta = (DefaultToSelf = "Widget", HideSelfPin = "true"))