I run into a strange hint message about using mirrors in a program that doesn't use mirrors, but uses custom elements. Peter pointed out to me that this is because how custom elements are integrated with the dart2js piepeline.

If this can't be fixed that easily, can we fix the hint/warning?

Here is a simple example that reproduces the problem:

    import 'dart:html';
    class A extends HtmlElement { A.created() : super.created(); }
    main() => document.register('x-a', A);

Compiling this with dart2js generates the following (clearly misleading) warning:

    Hint: 3 methods retained for use by dart:mirrors out of 865 total methods (0%).