Change value type of timeout and maximumAge in PositionOptions

Regarding Geolocation API recommendation, The type of timeout and maximumAge
are changed to unsigned int from int, therefore those values could be over
int range.(http://www.w3.org/TR/geolocation-API/#position_options_interface)

BUG=368184

Review URL: https://codereview.chromium.org/285673002

git-svn-id: svn://svn.chromium.org/blink/trunk@174668 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Timeline section of devtools flickering of unwanted scroll bar seen in 'Records' row.

BUG=376250

Review URL: https://codereview.chromium.org/297863003

git-svn-id: svn://svn.chromium.org/blink/trunk@174669 bbb929c8-8fbe-4397-9dbb-9b2b20218538