Add new results for fast/css/font-face-synthetic-bold-italic.html

Add pixel results for the fast/css/font-face-synthetic-bold-italic.html
test which was modified in r158683.

TBR=leviw@chromium.org
BUG=

Review URL: https://codereview.chromium.org/25631006

git-svn-id: svn://svn.chromium.org/blink/trunk@158726 bbb929c8-8fbe-4397-9dbb-9b2b20218538