LGTM, with one nit.
http://gwt-code-reviews.appspot.com/132815/diff/3015/3018 File user/test/com/google/gwt/core/StackTraceLineNumbersTest.gwt.xml (right): http://gwt-code-reviews.appspot.com/132815/diff/3015/3018#newcode2 Line 2: <!-- Copyright 2008 Google Inc. --> Copyright date. http://gwt-code-reviews.appspot.com/132815 -- http://groups.google.com/group/Google-Web-Toolkit-Contributors