Disable CustomEventTest.InitWithSerializedScriptValue

BUG=317669
TBR=jww@chromium.org

Review URL: https://codereview.chromium.org/64683008

git-svn-id: svn://svn.chromium.org/blink/trunk@161726 bbb929c8-8fbe-4397-9dbb-9b2b20218538