Migrate all LayoutTests/dart/dom to main repo.

client/tests/client/dom/HiddenDom1Test.dart

Index: client/tests/client/dom/HiddenDom1Test.dart
diff --git a/client/tests/client/dom/HiddenDom1Test.dart b/client/tests/client/dom/HiddenDom1Test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..b0a5597fa6b132068d35e52c764f9825a8c8678c
--- /dev/null
+++ b/client/tests/client/dom/HiddenDom1Test.dart
@@ -0,0 +1,44 @@
+#library('HiddenDom1Test');
+#import('../../../testing/unittest/unittest.dart');
+#import('dart:html');
+
+// Test that the dart:html API does not leak native jsdom methods:
+//   onfocus setter.
+
+main() {
+  forLayoutTests();
+
+  test('test1', () {
+    document.body.elements.add(new Element.html(@'''
+<div id='div1'>
+Hello World!
+</div>'''));
+    Element e = document.query('#div1');
+    Expect.isTrue(e != null);
+
+    checkNoSuchMethod(() { confuse(e).onfocus = null; });
+  });
+
+}
+
+class Decoy {
+  void set onfocus(x) { throw 'dead code'; }
+}
+
+confuse(x) => opaqueTrue() ? x : (opaqueTrue() ? new Object() : new Decoy());
+
+/** Returns [:true:], but in a way that confuses the compiler. */
+opaqueTrue() => true;  // Expand as needed.
+
+checkNoSuchMethod(action()) {
+  var ex = null;
+  try {
+    action();
+  } catch (var e) {
+    ex = e;
+  }
+  if (ex === null)
+    Expect.fail('Action should have thrown exception');
+
+  Expect.isTrue(ex is NoSuchMethodException, 'ex is NoSuchMethodException');
+}