plugins/evaluate-js-after-removing-plugin-element.html times out in WebKit1 on SnowLeopard. It times out because WebKit/mac's OOP plugin implementation doesn't allow plugins to execute JavaScript after NPP_Destroy has been called.
<rdar://problem/8626122>
There's also some tests disabled due to that: # <rdar://problem/7091352> Some plug-in tests show missing NPP_Destroy call plugins/netscape-destroy-plugin-script-objects.html plugins/open-and-close-window-with-plugin.html plugins/geturlnotify-during-document-teardown.html
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.