Fixing up WebComponents types & tests

tests/html/shadowroot_test.dart

Index: tests/html/shadowroot_test.dart
diff --git a/tests/html/shadowroot_test.dart b/tests/html/shadowroot_test.dart
index 1b027c6d1929d16f37ab3cfc48207f25f200f1d6..56cf13b5c0d62864a9105c2008c703a5c66e3dc7 100644
--- a/tests/html/shadowroot_test.dart
+++ b/tests/html/shadowroot_test.dart
@@ -18,10 +18,10 @@ main() {
 
     // If it's supported, then it should work. Otherwise should fail.
     if (isSupported) {
-      var shadowRoot = new DivElement().webkitCreateShadowRoot();
+      var shadowRoot = new DivElement().createShadowRoot();
       expect(shadowRoot, isShadowRoot);
     } else {
-      expect(() => new DivElement().webkitCreateShadowRoot(), throws);
+      expect(() => new DivElement().createShadowRoot(), throws);
     }
   });
 }