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

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

Index: sky/sdk/lib/framework/components2/input.dart
diff --git a/sky/sdk/lib/framework/components2/input.dart b/sky/sdk/lib/framework/components2/input.dart
index 951e2bde117a2e0186a7e74ac987fd946005168c..c8a5477fb728d2d0aa85a027cc70faae2f72de92 100644
--- a/sky/sdk/lib/framework/components2/input.dart
+++ b/sky/sdk/lib/framework/components2/input.dart
@@ -50,10 +50,17 @@ class Input extends Component {
   //   padding: 7px;
   //   border-bottom: 2px solid ${Blue[500]};''';
 
-  ValueChanged onChanged;
   String placeholder;
+  ValueChanged onChanged;
   bool focused = false;
 
+  void syncFields(Input source) {
+    placeholder = source.placeholder;
+    onChanged = source.onChanged;
+    focused = source.focused;
+    super.syncFields(source);
+  }
+
   String _value = '';
   bool _isAttachedToKeyboard = false;
   EditableString _editableValue;