GitLab

https://boringssl.googlesource.com/boringssl/+log/d7421ebf6cae07051caf657016f160585b64f8a6..3ac32b1eda0da7a99d9c2b6c605fe50af80ccd90

In doing so, switch crypto/curve25519.h to use the new BoringSSL curve25510
code to avoid shipping two copies. This includes a small subgroup check, so
callers need to be tweaked slightly.

BUG=none

Review URL: https://codereview.chromium.org/1459783002

Cr-Commit-Position: refs/heads/master@{#360507}