LeakExpectations: add more worker tests

BUG=364390
NOTRY=true
TBR=hajimehoshi

Review URL: https://codereview.chromium.org/405353007

git-svn-id: svn://svn.chromium.org/blink/trunk@178634 bbb929c8-8fbe-4397-9dbb-9b2b20218538