Delete unused geolocation client mocks from web.

This is a followup to patch 144023010

BUG=336263

Review URL: https://codereview.chromium.org/140253009

git-svn-id: svn://svn.chromium.org/blink/trunk@165651 bbb929c8-8fbe-4397-9dbb-9b2b20218538