HTML5 video controller in fullscreen is partly off-screen (at least on youtube) using ClickToFlash
Created attachment 100384 [details]
Committed r90797: <http://trac.webkit.org/changeset/90797>
It seems fine to make these CSS rules !important.
But I don’t think this is a real fix to the underlying problem. Other CSS properties could be set, ones not listed in this stylesheet at all, and those would affect fullscreen mode and the video controller.
The problem of styles on the page affecting the controller is an architectural one that needs a real solution at some point. This is one of multiple problems that stem from building the fullscreen mode for video out of the general fullscreen feature; that implementation detail should not show through.
While I don’t know exactly what the solution is, I am sure there are some simple ways to isolate the fullscreen controller from other page content.
Bug #61843 and #61848 would provide a real solution for this problem by implementing the video-full-screen mode in WebKit2. (As opposed to making the element-full-screen mode simulate the behavior and side-effects of video-full-screen mode.)
For clickability: Bug #61848