Add cross-origin test with credentials.

pkg/unittest/lib/html_config.dart

Index: pkg/unittest/lib/html_config.dart
diff --git a/pkg/unittest/lib/html_config.dart b/pkg/unittest/lib/html_config.dart
index 3d87f98a77b9ea89c1cb406646c93778d2ad583d..b0225e0376a73799e4884168800e305e606771f9 100644
--- a/pkg/unittest/lib/html_config.dart
+++ b/pkg/unittest/lib/html_config.dart
@@ -143,6 +143,19 @@ class HtmlConfiguration extends Configuration {
   }
 }
 
+/**
+ * Examine the url for this test to determine what the cross-origin port is for
+ * this test.

[Siggi Cherem (dart-lang), 2013/01/04 01:49:43]

nit: rephase, maybe "The value of the 'crossOriginPort' argument in the
[window.location]."

[Emily Fortuna, 2013/01/04 23:26:54]

Done.

+ */
+int getCrossOriginPortNumber() {

[Siggi Cherem (dart-lang), 2013/01/04 01:49:43]

I think this should not be in unittest. I mean, it feels very specific about how
we use test.dart + cross-domain tests. I think of unittest (and these
configurations) as something more general that is also used without test.dart.

Can we move this directly to the test that uses this or maybe provide a separate
library that can be imported by those tests?

Some additional suggestions on the code:
- 'PortNumber' sounds reduntant, how about just 'Port'?
- convert this into a getter: int get crossOriginPort { ... }

[Emily Fortuna, 2013/01/04 23:26:54]

Good point. Removed.

+  var searchUrl = window.location.search;
+  var crossOriginStr = 'crossOriginPort=';
+  var index = searchUrl.indexOf(crossOriginStr);
+  var nextArg = searchUrl.indexOf('&', index);
+  return int.parse(searchUrl.substring(index + crossOriginStr.length,
+      nextArg == -1 ? searchUrl.length : nextArg));
+}
+
 void useHtmlConfiguration([bool isLayoutTest = false]) {
   configure(new HtmlConfiguration(isLayoutTest));
 }