Cross frame access tests

client/tests/client/dom/CrossFrameTest.dart

+#library('CrossFrameTest');
+#import('../../../testing/unittest/unittest.dart');
+#import('dart:dom');
+
+main() {
+  forLayoutTests();
+
+  test('contentWindow', () {
+      final iframe = document.createElement('iframe');
+      document.body.appendChild(iframe);
+      Window frameWindow = iframe.contentWindow;
+
+      // Test this field to ensure a valid Dart wrapper.

[sra1, 2012/02/24 03:38:30]

Since all native classes implement this, it is not distinguishing between the
wrapper and a native object.
Since dartObjectLocalStorages is unused unless the wrapping dart:html library
has wrapped it, it will always be null.
I want to get rid of dartObjectLocalStorage if possible after the direct
dart:html lands.

Is there something else you can test?

If the issue is lack of access to private methods, I think it is OK for dart:dom
to export a public testing class like this:

class DOMTesting {
  bool static isDOMWindowCrossFrame(object) => object is __DOMWindowCrossFrame;
}

Longer term the language needs to make it possible for tests to be in library /
package / whatever.

[vsm, 2012/02/26 01:52:10]

This is effectively verifying that the object belongs to this frame - i.e., it
inherits from this frame's Object proto.

Without window wrapper, this check failed as the window object was not decorated
with a dartObjectLocalStorage getter. 

+      Expect.isNull(frameWindow.dartObjectLocalStorage);
+
+      // Ensure that the frame's document is inaccessible via window.
+      Expect.throws(() => frameWindow.document);
+    });
+
+  test('contentDocument', () {
+      final iframe = document.createElement('iframe');
+      document.body.appendChild(iframe);
+
+      // Ensure that the frame's document is inaccessible.
+      Expect.throws(() => iframe.contentDocument);
+      });

[antonm, 2012/02/24 15:31:24]

nit: -2 spaces, please

[vsm, 2012/02/26 01:52:10]

Done.

+}