In r54084 it is no longer possible to initiate a drag from selected text in the source view of the Resources pane. The initial mouse down clears the selection instead of initiating a drag. This works correctly in a build of WebKit from earlier in the week.
<rdar://problem/7594381>
Fixed in http://trac.webkit.org/changeset/54133. https://bugs.webkit.org/show_bug.cgi?id=34400