https://bugs.webkit.org/show_bug.cgi?id=78799

Reviewed by Gustavo Noronha Silva.

* UIProcess/API/gtk/WebKitPrintOperation.cpp:
(webkitPrintOperationRunDialogUnix): Enable printing in reverse
order option in print dialog.
* WebProcess/WebPage/gtk/WebPrintOperationGtk.cpp:
(WebKit::PrintPagesData::PrintPagesData): Initialize sheetNumber
and lastPagePosition depending on whether printing is in reverse
order or not.
(WebKit::PrintPagesData::incrementPageSequence): Use a negative
increment step when printing in reverse order. Fix page
incrementing when printing only odd/even pages broken in previous
commit due to merge conflicts.
(WebKit::WebPrintOperationGtk::WebPrintOperationGtk): Initialize
reverse printing to false.
* WebProcess/WebPage/gtk/WebPrintOperationGtk.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@108086 268f45cc-cd09-0410-ab3c-d52691b4dbfc