If a plug-in stores its MIME type information in a plist in ~/Library/Preferences/ but the plist doesn't yet exist, WebKit2 needs to load the plug-in bundle and call createPluginMIMETypesPreferences to have the file created.
Created attachment 92866 [details]
Comment on attachment 92866 [details]
Committed r86097: <http://trac.webkit.org/changeset/86097>
http://trac.webkit.org/changeset/86097 might have broken GTK Linux 64-bit Debug