Loading Gmail gives me multiple leaks from -[WebBasePluginPackage pListForPath:createFile:]. I'll upload the leak report as an attachment.
Created attachment 21753 [details] Leak report
I think that leak is inside the Java plugin itself rather than WebKits plugin code.
Should I file a bug with the Apple Java team?
Yes please!
Mass closing plug-in bugs, as plug-in support has been removed from WebKit. Please comment and/or reopen if this still affects WebKit in some way.