Fix actors disappearing for a tick when swapping to the frozen actor.

OpenRA.Game/Traits/Player/FrozenActorLayer.cs

@@ -253,6 +253,10 @@ namespace OpenRA.Traits
 		}
 
 		void ITick.Tick(Actor self)
+		{
+			// Update visibility at the end of the tick to make sure that
+			// the fog/shroud state has been updated for the tick
+			self.World.AddFrameEndTask(w =>
 			{
 				UpdateDirtyFrozenActorsFromDirtyBins();
 
@@ -281,6 +285,7 @@ namespace OpenRA.Traits
 
 				foreach (var fa in frozenActorsToRemove)
 					Remove(fa);
+			});
 		}
 
 		void UpdateDirtyFrozenActorsFromDirtyBins()