Remove one more use of mirrors: Components now have to explicitly sync their fields.

sky/sdk/lib/framework/components2/icon.dart

Index: sky/sdk/lib/framework/components2/icon.dart
diff --git a/sky/sdk/lib/framework/components2/icon.dart b/sky/sdk/lib/framework/components2/icon.dart
index 60cdb212ad76b567eb30cf597c6780a489038e5b..e5a6b46a60db62e64682350ffc1340d363e50c95 100644
--- a/sky/sdk/lib/framework/components2/icon.dart
+++ b/sky/sdk/lib/framework/components2/icon.dart
@@ -18,6 +18,12 @@ class Icon extends Component {
   int size;
   String type;
 
+  void syncFields(Icon source) {
+    size = source.size;
+    type = source.type;
+    super.syncFields(source);
+  }
+
   UINode build() {
     String category = '';
     String subtype = '';