The overflow scroll area's scrollbar on YouTube will correctly show an inactive look when the window is blurred. But focusing the window again does not bring back the active scrollbar look. See screenshot.
Created attachment 23796 [details]
Screenshot showing the bug
Not the scrollbar's fault. The focus controller is buggy and lying.
Page* page = renderer()->document()->frame()->page();
return page && page->focusController()->isActive();
This is a bug that just happens to have been exposed by the scrollbar.
Created attachment 23830 [details]
Created attachment 23831 [details]
Comment on attachment 23830 [details]
Comment on attachment 23831 [details]
Tim meant to plus this one.
Fixed in r36919.