checker.py and error_handlers.py shouldn't have to know how to parse and interpret patches.
We can probably get rid of the PatchStyleErrorHandler altogether by renaming the DefaultStyleErrorHandler to StyleErrorHandler and having it accept an optional array of line numbers (the line numbers of the modified lines). We probably also want to move the style_checker.check_patch() method to style/main.py and have the style_checker.check_file() method accept an optional array of line numbers, similar to the above. This way only style/main.py needs to be aware of patch-related code. This will have other benefits for future patches as well.
Created attachment 53098 [details] Proposed patch
This report was originally to move the patch-related code to a separate file, but for now it would be sufficient and better simply to move that code into a separate class.
Comment on attachment 53098 [details] Proposed patch Looks sane.
Comment on attachment 53098 [details] Proposed patch Clearing flags on attachment: 53098 Committed r57467: <http://trac.webkit.org/changeset/57467>
All reviewed patches have been landed. Closing bug.