LeakExpectations: suppress crash from multiple-register.html

BUG=397892
TBR=hajimehoshi
NOTRY=true

Review URL: https://codereview.chromium.org/415403003

git-svn-id: svn://svn.chromium.org/blink/trunk@178995 bbb929c8-8fbe-4397-9dbb-9b2b20218538