Looks like this is not needed anymore.
Created attachment 211533 [details] Patch
Nice!
Comment on attachment 211533 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=211533&action=review > Source/WebCore/rendering/RenderDeprecatedFlexibleBox.cpp:-135 > - FeatureObserver::observe(&document(), FeatureObserver::DeprecatedFlexboxChrome); > - else if (url.protocolIs("chrome-extension")) > - FeatureObserver::observe(&document(), FeatureObserver::DeprecatedFlexboxChromeExtension); > - else > - FeatureObserver::observe(&document(), FeatureObserver::DeprecatedFlexboxWebContent); I guess we can nuke those FeatureObserver enum values too.
Comment on attachment 211533 [details] Patch Clearing flags on attachment: 211533 Committed r155689: <http://trac.webkit.org/changeset/155689>
All reviewed patches have been landed. Closing bug.