5831cfb1bb
A new overlay was not being marked as an explicitly added source, even if it's within the directory of an analysis context. As a result, errors were not being reported. I believe this only happens if there's no underlying file. Therefore it seems difficult to reproduce in an IDE, but it comes up in a stress test. BUG= R=brianwilkerson@google.com Review URL: https://codereview.chromium.org/1753083003 .