Reset background color in fullscreen Safari
Reset background color in fullscreen Safari

Safari sets background color of fullscreen elements to white via user
agent styles. This can be seen on before/after pages when switching to
fullscreen mode.

REDMINE-16802

tf/pageflow,codevise/pageflow,codevise/pageflow,tf/pageflow,codevise/pageflow,codevise/pageflow,tf/pageflow,tf/pageflow