Check that interface constructors and default class constructors are compatible.

client/touch/Momentum.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Implementations can be used to simulate the deceleration of an element within
  * a certain region. To use this behavior you need to provide an initial
  * velocity that is meant to represent the gesture that is initiating this
  * deceleration. You also provide the bounds of the region that the element
  * exists in, and the current offset of the element within that region. The
@@ skipping 362 matching lines @@
   num _stepTimeout;
   bool _decelerating;
   MomentumDelegate _delegate;
   int _nextY;
   int _nextX;
   Coordinate _minCoord;
   Coordinate _maxCoord;
   num _customDecelerationFactor;
   num _defaultDecelerationFactor;
 
-  TimeoutMomentum(this._delegate, [defaultDecelerationFactor = 1])
+  TimeoutMomentum(this._delegate, [num defaultDecelerationFactor = 1])
     : _defaultDecelerationFactor = defaultDecelerationFactor,
       _decelerating = false,
       _moves = new Queue<_Move>(),
       physicsX = new SingleDimensionPhysics(),
       physicsY = new SingleDimensionPhysics();
 
   /**
    * Calculate and return the moves for the deceleration motion.
    */
   void _calculateMoves() {
@@ skipping 151 matching lines @@
 
   Coordinate get destination() {
     if (!_moves.isEmpty()) {
       final lastMove = _moves.last();
       return new Coordinate(lastMove.x, lastMove.y);
     } else {
       return null;
     }
   }
 }