To reproduce: 1. Add http://www.flashexample.com/ to your Top Sites 2. Go to Top Sites 3. Click on flashexample.com 4. Go back to Top Sites The snapshot for flashexample.com does not contain the flash plugins on that page.
I think this is due to WebKit2's snapshot APIs not capturing windowed plugins.
<rdar://problem/9249665>
This also prevents pixel tests from working correctly on tests that use windowed plugins.