TestExpectations: svg/as-object/nested-embedded-svg-size-changes-no-layout-triggers-2.html is flaky

BUG=282634
TBR=fmalita@chromium.org

Review URL: https://codereview.chromium.org/23651008

git-svn-id: svn://svn.chromium.org/blink/trunk@157018 bbb929c8-8fbe-4397-9dbb-9b2b20218538