Update instructions:
git clone https://boringssl.googlesource.com/boringssl
git checkout <commithash>
(currently 82aa28fa
)mkdir -p third_party/boringssl/src
cp -R <BoringSSL source tree>/* third_party/boringssl/src
cp <BoringSSL source tree>/build/crypto/err/err_data.c third_party/boringssl