Prevent module system from loading arbitrary modules

BUG=603725

Review URL: https://codereview.chromium.org/1902263006

Cr-Commit-Position: refs/heads/master@{#388526}
(cherry picked from commit 15574e83265d53f65ce653de0db34c738bdb89f9)

Review URL: https://codereview.chromium.org/1912783002 .

Cr-Commit-Position: refs/branch-heads/2704@{#169}
Cr-Branched-From: 6e53600def8f60d8c632fadc70d7c1939ccea347-refs/heads/master@{#386251}
1 file changed