Allow the installability check to respect --unsafely-treat-insecure-origin-as-secure.

InstallableManager uses SecurityStateTabHelper to check the security
status of a tab, and strictly verifies the status of the SSL
certificate. However, this means that any origins whitelisted using the
--unsafely-treat-insecure-origin-as-secure flag are still regarded as
insecure for the purposes of the check.

This CL allows InstallableManager to respect the flag by exposing
content::IsWhitelistedAsSecureOrigin in content/public. This allows the
strictness of the check to be maintained whilst allowing users of the
flag to have their sites considered as installable (e.g. testing sites
on local network IP addresses).

BUG=864391

Change-Id: Id801cc74524e760a1a502dd2a7de7b026cb86c33
Reviewed-on: https://chromium-review.googlesource.com/c/1401830
Commit-Queue: Dominick Ng <dominickn@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Reviewed-by: Ben Wells <benwells@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622182}
5 files changed