Change a couple vars -> finals.

client/html/src/ElementWrappingImplementation.dart

Index: client/html/src/ElementWrappingImplementation.dart
diff --git a/client/html/src/ElementWrappingImplementation.dart b/client/html/src/ElementWrappingImplementation.dart
index ace8e817300517925b9cf34c7fae35b2bc8134fb..69daec26cbc8ae63c26ffae6648b2cf723a780d6 100644
--- a/client/html/src/ElementWrappingImplementation.dart
+++ b/client/html/src/ElementWrappingImplementation.dart
@@ -149,7 +149,7 @@ class FrozenElementList implements ElementList {
   }
 
   Collection map(f(Element element)) {
-    var out = [];
+    final out = [];
     for (Element el in this) {
       out.add(f(el));
     }
@@ -157,7 +157,7 @@ class FrozenElementList implements ElementList {
   }
 
   ElementList filter(bool f(Element element)) {
-    var out = new _ElementList([]);
+    final out = new _ElementList([]);
     for (Element el in this) {
       if (f(el)) out.add(el);
     }