http/tests/serviceworker/onactivate-script-error.html times out on Win

BUG=431172
NOTRY=true

Review URL: https://codereview.chromium.org/697113003

git-svn-id: svn://svn.chromium.org/blink/trunk@184953 bbb929c8-8fbe-4397-9dbb-9b2b20218538