Big merge from experimental to bleeding edge.

runtime/lib/double_patch.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.
 // Dart core library.
 
 // VM implementation of double.
 
 patch class double {
-  /* patch */
-  static double parse(String string) native "Double_parse";
+  static double _parse(String string) native "Double_parse";
+
+  /* patch */ static double parse(String str,
+                                  [double handleError(String str)]) {
+    if (handleError == null) return _parse(str);
+    try {
+      return _parse(str);
+    } on FormatException {
+      return handleError(str);
+    }
+  }
 }