Dismissable: correct handling of a drag that ends with a fling

examples/widgets/page_scrollable.dart

@@ -56,7 +56,6 @@ class TestApp extends App {
   }
 
   Widget buildCard(CardModel cardModel) {
-    print("SKY buildCard ${cardModel.label}");
     Widget card = new Card(
       color: cardModel.color,
       child: new Container(

packages/flutter/lib/widgets/dismissable.dart

@@ -153,7 +153,10 @@ class Dismissable extends StatefulComponent {
     _dragUnderway = false;
     if (_isHorizontalFlingGesture(event)) {
       _dragX = event.velocityX.sign;
-      _fadePerformance.fling(velocity: event.velocityX.abs() * _kFlingVelocityScale);
+      if (_fadePerformance.isCompleted)
+        _startResizePerformance();
+      else
+        _fadePerformance.fling(velocity: event.velocityX.abs() * _kFlingVelocityScale);
     } else {
       _fadePerformance.reverse();
     }