When a snapshotted plugin gets restarted, there is an abrupt swap as the snapshot disappears and the plugin loads. Replace this with a cross-fade.
I'll implement the WebCore part to detect a restarted plugin, and have the RenderEmbeddedObject draw the snapshot for a while as the plugin appears, but the main crossfade will be done in Apple-specific code. Other platforms will just have to do whatever it takes to animate the opacity of their plugins.
Created attachment 196333 [details]
Committed r147579: <http://trac.webkit.org/changeset/147579>