Work around Safari for-in bug.

dart/sdk/lib/_internal/compiler/js_lib/js_mirrors.dart

Index: dart/sdk/lib/_internal/compiler/js_lib/js_mirrors.dart
diff --git a/dart/sdk/lib/_internal/compiler/js_lib/js_mirrors.dart b/dart/sdk/lib/_internal/compiler/js_lib/js_mirrors.dart
index e34319e58c2b6d8aee4ed75c3b8490822bad867e..81240e9d48aa6d62b53f94b2c67e34d77e6f5f5a 100644
--- a/dart/sdk/lib/_internal/compiler/js_lib/js_mirrors.dart
+++ b/dart/sdk/lib/_internal/compiler/js_lib/js_mirrors.dart
@@ -2236,7 +2236,9 @@ class JsClosureMirror extends JsInstanceMirror implements ClosureMirror {
     String callPrefix = "${JS_GET_NAME(JsGetName.CALL_PREFIX)}\$";
     var extractCallName = JS('', r'''
 function(reflectee) {
-  for (var property in reflectee) {
+  var properties = Object.keys(reflectee.constructor.prototype);

[floitsch, 2015/02/23 14:14:26]

Are you sure this is equivalent?

Does the JsClosureMirror get invoked for classes that implement the 'call'
method? If yes, then the call-property might be on a super.

Safari's for-in can't be completely broken (otherwise every page would have this
problem). I would let this one in, and hope that it isn't affected.

[ahe, 2015/02/23 15:04:45]

It doesn't. It only gets invoked for actual closures that implements the Closure
interface (which is private to dart2js' platform implementation libraries).

That's probably a bug, but the solution is not to use for-in here. This class
assumes that reflectee is an instance of Closure.
I don't know precisely how for-in is broken, but I don't see how this situation
is different from the other for-ins. So I'd strongly prefer to not rely on
for-in.

+  for (var i = 0; i < properties.length; i++) {
+    var property = properties[i];
     if (# == property.substring(0, #) &&
         property[#] >= '0' &&
         property[#] <= '9') return property;