Fixing broken tests because of mismatch of suppressed warnings.

sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index ebf1be96c6f16909e1e6afd4397d670203a40e9e..7bc3810a6dd983d6df94f2afa19ee04079980ed2 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -29818,11 +29818,12 @@ class _Bindings {
   static void _removeChild(Node parent, Node child) {
     child._templateInstance = null;
     if (child is Element && (child as Element).isTemplate) {
+      Element childElement = child;
       // Make sure we stop observing when we remove an element.
-      var templateIterator = child._templateIterator;
+      var templateIterator = childElement._templateIterator;
       if (templateIterator != null) {
         templateIterator.abandon();
-        child._templateIterator = null;
+        childElement._templateIterator = null;
       }
     }
     child.remove();