Disable File Browsing Chrome/Firefox
Solution 1:
You can use Chrome policies to disable file browsing. See https://support.google.com/chrome/a/answer/187202?hl=en for more details about how to use Group Policy to configure policies for Chrome.
For file browsing in particular, you probably want to set AllowFileSelectionDialogs to "disabled", and to add "file://" to the URL blacklist. See:
http://www.chromium.org/administrators/policy-list-3#AllowFileSelectionDialogs http://www.chromium.org/administrators/policy-list-3#URLBlacklist