Rebaseline fast/frames/iframe-scaling-with-scroll.html

BUG=358964
TBR=leviw

Review URL: https://codereview.chromium.org/213833023

git-svn-id: svn://svn.chromium.org/blink/trunk@170635 bbb929c8-8fbe-4397-9dbb-9b2b20218538