Node::HasIDFlag and Node::HasClassFlag can be replaced with ElementAttributeData,
which doesn't need any hashtable lookup.
Created attachment 126208 [details]
Ryosuke, Andreas, could you take a look?
Note that I don't see any significant performance impact on Dromaeo.
Comment on attachment 126208 [details]
Great idea! r=me
Waiting Bug 78070 is resolved as rniwa's suggestion at irc.
Committed r108449: <http://trac.webkit.org/changeset/108449>