Mark fast/dom/Geolocation/error-clear-watch.html as [ Pass Timeout ] on Linux

Flakyness dashboard:
http://test-results.appspot.com/dashboards/flakiness_dashboard.html#master=ChromiumWebkit&tests=fast/dom/Geolocation/error-clear-watch.html

BUG=373430
TBR=mvanouwerkerk@chromium.org, senorblanco@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/722383002

git-svn-id: svn://svn.chromium.org/blink/trunk@185338 bbb929c8-8fbe-4397-9dbb-9b2b20218538