Replace "roll out" terminology with "revert

This old terminology is confusing and we don't use it anymore.

Author: mcatanzaro

docs/Ports/WebKitGTK and WPE WebKit/TipsForMaintainers.md

@@ -24,7 +24,7 @@ You are ultimately responsible for finding reviewers to ensure your pull request
 
 ## Zero Regressions?
 
-WebKit has a zero regressions policy, meaning any committer can revert any commit if it's found to introduce a regression. That said, apply common sense. If buildbots are broken, that's an emergency and it makes sense to revert the offending commit now and then think about how to fix the problem later. If WebKitGTK no longer works at all or has suffered some other severe regression, then again, revert the offending commit now and ask questions later. But usually the issue is more minor, and it would make more sense to talk to the developer who introduced the issue before rolling it out, or to not roll it out at all. Developers usually don't enjoy seeing work rolled out, and you won't make friends by rolling out commits unnecessarily. It's not unusual for a commit to fix a major issue while also introducing a less-serious issue; it wouldn't make sense to revert a commit in blind adherence to zero regressions if that would reduce the quality of WebKit overall. Generally, cross-platform commits should be rolled out only if the regression is severe. Platform-specific WPE/GTK commits can be rolled out more aggressively.
+WebKit has a zero regressions policy, meaning any committer can revert any commit if it's found to introduce a regression. That said, apply common sense. If buildbots are broken, that's an emergency and it makes sense to revert the offending commit now and then think about how to fix the problem later. If WebKitGTK no longer works at all or has suffered some other severe regression, then again, revert the offending commit now and ask questions later. But usually the issue is more minor, and it would make more sense to talk to the developer who introduced the issue before reverting it, or to not revert it at all. Developers usually don't enjoy seeing work reverted, and you won't make friends by reverting commits unnecessarily. It's not unusual for a commit to fix a major issue while also introducing a less-serious issue; it wouldn't make sense to revert a commit in blind adherence to zero regressions if that would reduce the quality of WebKit overall. Generally, cross-platform commits should be reverted only if the regression is severe. Platform-specific WPE/GTK commits can be reverted more aggressively.
 
 ## Security