TestExpectations update, gardening.

virtual/serviceworker/http/tests/serviceworker/registration.html
virtual/threaded/animations/sample-on-last-keyframe.html

BUG=352703,352705
TEST=
TBR=zmo@chromium.org

Review URL: https://codereview.chromium.org/195763024

git-svn-id: svn://svn.chromium.org/blink/trunk@169263 bbb929c8-8fbe-4397-9dbb-9b2b20218538