FontLoader checks for layout and then schedules style recalc unnecessarily

This code is just dead.  Forcing a style recalc won't cause needsLayout
to go from true to false.

I also fixed this method to just abort if the view is gone.  We probably
were already never hitting that case, but if we're going to null-check
FrameView, we might as well bail in the null case.

Review URL: https://chromiumcodereview.appspot.com/20537006

git-svn-id: svn://svn.chromium.org/blink/trunk@155071 bbb929c8-8fbe-4397-9dbb-9b2b20218538