RenderStyle no longer needs to be friends with  RenderSVGResource

Removing another friend declaration that is no longer needed, all the
remeaning ones are still needed but my currentcolor change shold allow
a couple more to be eliminated.

BUG=237268
R=eseidel@chromium.org

Review URL: https://chromiumcodereview.appspot.com/19720005

git-svn-id: svn://svn.chromium.org/blink/trunk@154715 bbb929c8-8fbe-4397-9dbb-9b2b20218538