ceil/floor/truncate/round return integers.

runtime/lib/integers.dart

 // Copyright (c) 2012, 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.
 
 // TODO(srdjan): fix limitations.
 // - shift amount must be a Smi.
 class _IntegerImplementation {
   factory _IntegerImplementation._uninstantiable() {
     throw new UnsupportedError(
         "_IntegerImplementation can only be allocated by the VM");
@@ skipping 113 matching lines @@
     } else {
       return EQUAL;
     }
   }
 
   int round() { return this; }
   int floor() { return this; }
   int ceil() { return this; }
   int truncate() { return this; }
 
+  double roundToDouble() { return this.toDouble(); }
+  double floorToDouble() { return this.toDouble(); }
+  double ceilToDouble() { return this.toDouble(); }
+  double truncateToDouble() { return this.toDouble(); }
+
   num clamp(num lowerLimit, num upperLimit) {
     if (lowerLimit is! num) throw new ArgumentError(lowerLimit);
     if (upperLimit is! num) throw new ArgumentError(upperLimit);
 
     // Special case for integers.
     if (lowerLimit is int && upperLimit is int) {
       if (lowerLimit > upperLimit) {
         throw new ArgumentError(lowerLimit);
       }
       if (this < lowerLimit) return lowerLimit;
@@ skipping 119 matching lines @@
     }
   }
   int _shlFromInt(int other) {
     throw const OutOfMemoryError();
   }
 
   int pow(int exponent) {
     throw "Bigint.pow not implemented";
   }
 }