Return the correct port from Uri, when port is 0 and scheme is either http or https.

tests/corelib/uri_path_test.dart

Index: tests/corelib/uri_path_test.dart
diff --git a/tests/corelib/uri_path_test.dart b/tests/corelib/uri_path_test.dart
index d1804f97b327ae54c1cba300cbedd5f94d81860b..6274e8b5ee731bcfba3102e230dccbc0010f46cd 100644
--- a/tests/corelib/uri_path_test.dart
+++ b/tests/corelib/uri_path_test.dart
@@ -47,12 +47,9 @@ void testPathSegments() {
 
     var uri1 = new Uri(pathSegments: segments);
     var uri2 = new Uri(path: path);
-    var uri3 = Uri.parse(path);
     check(uri1);
     check(uri2);
-    check(uri3);
-    Expect.equals(uri1, uri3);
-    Expect.equals(uri2, uri3);
+    Expect.equals(uri1, uri2);
   }
 
   test("", []);