1. Bookmark a pdf and edit the bookmark properties to load it in the sidebar. a. https://talkgadget.google.com/talkgadget/client displays the same issue 2. Click bookmark 3. Side bar opens displaying a black rectangle Loading youtube or google maps street view in the sidebar does not trigger this issue.
Note for 1.a if you are not signed into your Google account you will need to before the issue is shown.
I see the same thing with ipc disabled.
Is this still a problem now that bug 529263 is fixed?