Add test for garbage collected window event listeners issue.

tests/html/native_gc_test.dart

 #library('NativeGCTest');
 #import('../../lib/unittest/unittest.dart');
 #import('../../lib/unittest/html_config.dart');
 #import('dart:html');
 
 main() {
   useHtmlConfiguration();
 
   test('EventListener', () {
       final int N = 1000000;
@@ skipping 12 matching lines @@
         div.on['test'].add((_) {
             // Only the final iteration's listener should be invoked.
             // Note: the reference to l keeps the entire list alive.
             Expect.equals(M - 1, l[N - 1]);
           }, false);
       }
 
       final event = new Event('test');
       div.on['test'].dispatch(event);
   });
+
+  test('WindowEventListener', () {
+    Element testDiv = new DivElement();
+    testDiv.id = '#TestDiv';
+    document.body.nodes.add(testDiv);
+    window.on.message.add((e) => testDiv.click());
+
+    for (int i = 0; i < 100; ++i) {
+      triggerMajorGC();
+    }
+
+    testDiv.on.click.add(expectAsync1((e) {}));
+    window.postMessage('test', '*');
+  });
 }
+
+void triggerMajorGC() {
+  List list = new List(1000000);

[Anton Muhin, 2012/07/06 16:17:01]

somewhat fragile, but, I don't know better approach except for exposing gc.

+  Element div = new DivElement();
+  div.on.click.add((e) => print(list[0]));

[Anton Muhin, 2012/07/06 16:17:01]

why?

[podivilov, 2012/07/10 08:33:52]

why not? :)

[Anton Muhin, 2012/07/10 08:41:38]

It's not obvious why code which promises to trigger GC needs to install any
event listeners.

On 2012/07/10 08:33:52, podivilov wrote:

[podivilov, 2012/07/10 11:03:47]

Is it possible that void foo() { List list = new List(1000000); } will be
compiled into no-op?
And shouldn't we somehow retain this list from embedder's code to make sure it
won't be collected on minor GC?

[Anton Muhin, 2012/07/10 11:36:16]

That's a good point, but in this case you'd better store into some global state,
as GC should collect div element, and therefore its closure and this reference
too.

But up to you.

On 2012/07/10 11:03:47, podivilov wrote:

+}