Mark svg/custom/object-sizing-no-width-height-change-content-box-size.xhtml for rebaseline after r174301

TBR=rhogan@chromium.org
BUG=238449

Review URL: https://codereview.chromium.org/297593002

git-svn-id: svn://svn.chromium.org/blink/trunk@174322 bbb929c8-8fbe-4397-9dbb-9b2b20218538