Fix tests by fixing a typo in Text due to one of my recent checkins.

TBR=abarth

Review URL: https://codereview.chromium.org/1191793004.

sdk/lib/widgets/basic.dart

@@ -381,7 +381,7 @@ class Inline extends LeafRenderObjectWrapper {
 }
 
 class Text extends Component {
-  Text(data, { String key, TextStyle this.style }) : super(key: key);
+  Text(this.data, { String key, TextStyle this.style }) : super(key: key);
   final String data;
   final TextStyle style;
   bool get interchangeable => true;