73fccff8ea
Also, mostly drop 'fileStamp' in SourceFileEdit. Only `-1` is kept when the file is a new one, in other cases it' `0`. As I can see, IDEA cares only about `-1`. We don't know modification stamps with the new analysis driver. But we know content hashes. R=brianwilkerson@google.com, paulberry@google.com BUG= Review URL: https://codereview.chromium.org/2518903002 .