Fixing up setting styles to invalidate on IE9.

tests/html/cssstyledeclaration_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library('CSSStyleDeclarationTest');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 
 main() {
@@ skipping 45 matching lines @@
 
     expect(style.color, equals("red"));
     expect(style.transform, equals("translate(10px, 20px)"));
   });
 
   test('Browser prefixes', () {
     var element = new DivElement();
     element.style.transform = 'translateX(10px)';
     document.body.elements.add(element);
 
-    var style = new CSSStyleDeclaration();
-
     element.getComputedStyle('').then(expectAsync1(
       (CSSStyleDeclaration style) {
         // Some browsers will normalize this, so it'll be a matrix rather than
         // the original string. Just check that it's something other than null.
         expect(style.transform.length, greaterThan(3));
       }
     ));
   });
+
+  // IE9 requires an extra poke for some properties to get applied.
+  test('IE9 Invalidation', () {
+    var element = new DivElement();
+    document.body.elements.add(element);
+
+    // Need to wait one tick after the element has been added to the page.
+    window.setTimeout(expectAsync0(() {
+      element.style.textDecoration = 'underline';
+      element.getComputedStyle('').then(expectAsync1(
+        (CSSStyleDeclaration style) {
+          expect(style.textDecoration, equals('underline'));
+        }
+      ));
+    }), 10);
+  });
 }