Make ~/, round, ceil, floor, truncate return ints. Remove toInt.

samples/swarm/swarm_ui_lib/touch/Scroller.dart

Index: samples/swarm/swarm_ui_lib/touch/Scroller.dart
diff --git a/samples/swarm/swarm_ui_lib/touch/Scroller.dart b/samples/swarm/swarm_ui_lib/touch/Scroller.dart
index 196d910854e6e0f2a632bde7d101e7872526b291..660d08ca08cfbf9846660a7f9de3039b5f5f23e1 100644
--- a/samples/swarm/swarm_ui_lib/touch/Scroller.dart
+++ b/samples/swarm/swarm_ui_lib/touch/Scroller.dart
@@ -351,8 +351,8 @@ class Scroller implements Draggable, MomentumDelegate {
   void throwDelta(num deltaX, num deltaY, [num decelerationFactor = null]) {
     Coordinate start = _contentOffset;
     Coordinate end = currentTarget;
-    int x = end.x.toInt();
-    int y = end.y.toInt();
+    int x = end.x.truncate();
+    int y = end.y.truncate();
     // If we are throwing in the opposite direction of the existing momentum,
     // cancel the current momentum.
     if (deltaX != 0 && deltaX.isNegative != (end.x - start.x).isNegative) {
@@ -361,8 +361,8 @@ class Scroller implements Draggable, MomentumDelegate {
     if (deltaY != 0 && deltaY.isNegative != (end.y - start.y).isNegative) {
       y = start.y;
     }
-    x += deltaX.toInt();
-    y += deltaY.toInt();
+    x += deltaX.truncate();
+    y += deltaY.truncate();
     throwTo(x, y, decelerationFactor);
   }