Include openssl/chacha.h rather than duplicate the prototype.

Less chance of problems should the prototype ever change. This doesn't
make it any more or less a circular dependency. (It actually isn't;
crypto/chacha doesn't use crypto/rand and CMakeLists.txt actually puts
rand above chacha anyway.)

Change-Id: Ia80289f801f76551737233f158755aac99ddd74a
Reviewed-on: https://boringssl-review.googlesource.com/5262
Reviewed-by: Adam Langley <agl@google.com>
1 file changed