This reverts revision 20001 and removes other instances of use_openssl since Chromium is removing the use_openssl flag and iOS no longer ships with NSS as of https://crrev.com/387011. BUG=chromium:601042 R=perkj@webrtc.org, torbjorng@webrtc.org Review URL: https://codereview.webrtc.org/1884233002 Cr-Commit-Position: refs/heads/master@{#12414}