Later versions of Safari allow you to Disable Cross-Origin Restrictions. Just enable the developer menu from Preferences >> Advanced, and select “Disable Cross-Origin Restrictions” from the develop menu.
see cross domain - Disabling same-origin policy in Safari - Stack Overflow
In Chrome, this can be done by launching with the flag --disable-web-security
or by using an extensión like Allow CORS: Access-Control-Allow-Origin.