ceil/floor/truncate/round return integers.

tests/corelib/double_floor2_test.dart

Index: tests/corelib/double_floor2_test.dart
diff --git a/tests/corelib/double_floor2_test.dart b/tests/corelib/double_floor2_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..b17a375b9f0b4cad6455f86b920d42eb9a815e9c
--- /dev/null
+++ b/tests/corelib/double_floor2_test.dart
@@ -0,0 +1,10 @@
+// Copyright (c) 2013, 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.
+
+main() {
+  Expect.throws(() => double.INFINITY.floor(), (e) => e is UnsupportedError);
+  Expect.throws(() => double.NEGATIVE_INFINITY.floor(),
+                (e) => e is UnsupportedError);
+  Expect.throws(() => double.NAN.floor(), (e) => e is UnsupportedError);
+}