Add default for Activity-Tick

OpenRA.Game/Activities/Activity.cs

@@ -82,7 +82,13 @@ namespace OpenRA.Activities
 			return ret;
 		}
 
-		public abstract Activity Tick(Actor self);
+		/// <summary>
+		/// Runs every timestep as long as this activity is active.
+		/// </summary>
+		public virtual Activity Tick(Actor self)
+		{
+			return NextActivity;
+		}
 
 		/// <summary>
 		/// Runs once immediately before the first Tick() execution.

OpenRA.Mods.Common/Activities/DeliverUnit.cs

@@ -50,12 +50,6 @@ namespace OpenRA.Mods.Common.Activities
 			QueueChild(new TakeOff(self));
 		}
 
-		public override Activity Tick(Actor self)
-		{
-
-			return NextActivity;
-		}
-
 		class ReleaseUnit : Activity
 		{
 			readonly Carryall carryall;
@@ -98,11 +92,6 @@ namespace OpenRA.Mods.Common.Activities
 					carryable.Detached(cargo);
 				});
 			}
-
-			public override Activity Tick(Actor self)
-			{
-				return NextActivity;
-			}
 		}
 	}
 }

OpenRA.Mods.Common/Activities/Transform.cs

@@ -168,11 +168,5 @@ namespace OpenRA.Mods.Common.Activities
 		{
 			return new Order(orderString, newActor, target, true);
 		}
-
-		public override Activity Tick(Actor self)
-		{
-			// Activity is a placeholder that should never run
-			return NextActivity;
-		}
 	}
 }