Force HTTPS and public keys for sandbox.google.com and subdomains.

      This would have helped mitigate a recent security bug.

BUG=172984
TEST=visit http://{plus,www,}.sandbox.google.com and make sure the request
is upgraded to HTTPS.

Review URL: https://codereview.chromium.org/12093100

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@180188 0039d316-1c4b-4281-b951-d872f2087c98