Update LeakExpectations wrt shared worker tests.

Sync expectations after r177178.

TBR=kouhei@chromium.org
BUG=364390
NOTRY=true

Review URL: https://codereview.chromium.org/344483004

git-svn-id: svn://svn.chromium.org/blink/trunk@177205 bbb929c8-8fbe-4397-9dbb-9b2b20218538