pulled out dart:ui import

Author: gaaclarke

flutter_frontend_server/test/to_string_test.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:io';
-import 'dart:ui' show Color;
 
 import 'package:litetest/litetest.dart';
 import 'package:path/path.dart' as path;
@@ -47,7 +46,8 @@ Future<void> main(List<String> args) async {
     ]));
     final ProcessResult runResult = Process.runSync(dart, <String>[regularDill]);
     checkProcessResult(runResult);
-    String paintString = '"Paint.toString":"Paint(${const Color(0xffffffff)})"';
+    String paintString =
+        '"Paint.toString":"Paint(Color(alpha: 1.0000, red: 1.0000, green: 1.0000, blue: 1.0000, colorSpace: ColorSpace.sRGB))"';
     if (buildDir.contains('release')) {
       paintString = '"Paint.toString":"Instance of \'Paint\'"';
     }