LayoutTest emulating geolocation with inspector

Adding LayoutTests for emulating geolocation positions using inspector.

BUG=345040

Review URL: https://codereview.chromium.org/172393006

git-svn-id: svn://svn.chromium.org/blink/trunk@167810 bbb929c8-8fbe-4397-9dbb-9b2b20218538