We have a mechanism to enable experimental settings via a environment variable called WEBKITGTK_EXPERIMENTAL_FEATURES. It seems like CSS Grid Layout could be something to be enabled this way at this moment. JFYI, there's not compilation flag for it.
Created attachment 221349 [details] Patch
Thanks for the patch. If this patch contains new public API please make sure it follows the guidelines for new WebKit2 GTK+ API. See http://trac.webkit.org/wiki/WebKitGTK/AddingNewWebKit2API
Why not just make it enabled by default when it's compiled in? Are there tests that depend on it being turned off?
(In reply to comment #3) > Why not just make it enabled by default when it's compiled in? Are there tests that depend on it being turned off? The thing I guess is that it's always built as it isn't behind any preprocessor guard. Knowing that it's a spec in WD status, that it's still prefixed in WebKit, and provided we have this ExperimentalFeatures thingy, I think it's a good idea to add it there.
(In reply to comment #3) > Why not just make it enabled by default when it's compiled in? Are there tests that depend on it being turned off? Like Sergio says the preprocessor guard was removed a while ago in r117613 (May 2012). So grid layout support is always compiled. There're tests turning on this feature but any of them turning it off.
Comment on attachment 221349 [details] Patch Clearing flags on attachment: 221349 Committed r162215: <http://trac.webkit.org/changeset/162215>
All reviewed patches have been landed. Closing bug.