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

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

Index: sky/sdk/lib/framework/components2/material.dart
diff --git a/sky/sdk/lib/framework/components2/material.dart b/sky/sdk/lib/framework/components2/material.dart
index 599a372a7024202a85d6893d7cd411747c3cdb45..3b0c891965bb17571165f05041787cbdcd2ae366 100644
--- a/sky/sdk/lib/framework/components2/material.dart
+++ b/sky/sdk/lib/framework/components2/material.dart
@@ -21,6 +21,12 @@ class Material extends Component {
   UINode content;
   int level;
 
+  void syncFields(Material source) {
+    content = source.content;
+    level = source.level;
+    super.syncFields(source);
+  }
+
   UINode build() {
     // TODO(eseidel): Add a shadow.
     // return new StyleNode(content, _shadowStyle[level]);