Fixing up measurement test.

lib/html/src/dartium_MutationObserverSupported.dart

Index: lib/html/src/dartium_MutationObserverSupported.dart
diff --git a/lib/html/dartium/nativewrappers.dart b/lib/html/src/dartium_MutationObserverSupported.dart
similarity index 58%
copy from lib/html/dartium/nativewrappers.dart
copy to lib/html/src/dartium_MutationObserverSupported.dart
index 44ab39e1ac7567e620f8402b566e4b492836d41e..f2055effc1d536732c50e24951d76b284de661ea 100644
--- a/lib/html/dartium/nativewrappers.dart
+++ b/lib/html/src/dartium_MutationObserverSupported.dart
@@ -2,7 +2,10 @@
 // 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('nativewrappers');
-
-class NativeFieldWrapperClass1 {
+/**
+ * Checks to see if the mutation observer API is supported on the current
+ * platform.
+ */
+static bool _isMutationObserverSupported() {
+  return true;
 }