[Extensions] More bindings hardening
Revision 83a4b3aa72d98fe4176b4a54c8cea227ed966570 missed a few
(c/r/resources/extensions).
BUG=468931
BUG=591164
Review URL: https://codereview.chromium.org/1840453002
Cr-Commit-Position: refs/heads/master@{#383541}