external/boringssl: Sync to 45210dd4e21ace9d28cb76b3f83303fcdd2efcce.

This includes the following changes:

https://boringssl.googlesource.com/boringssl/+log/a62dbf88d8a3c04446db833a1eb80a620cb1514d..45210dd4e21ace9d28cb76b3f83303fcdd2efcce

Test: BoringSSL CTS Presubmits.
Change-Id: I2f3cc22fb906078f64bc2af020fa14c3d0875c81
diff --git a/sources.bp b/sources.bp
index 8cf85c0..377c715 100644
--- a/sources.bp
+++ b/sources.bp
@@ -87,7 +87,6 @@
         "src/crypto/cpu-ppc64le.c",
         "src/crypto/crypto.c",
         "src/crypto/curve25519/spake25519.c",
-        "src/crypto/curve25519/x25519-x86_64.c",
         "src/crypto/dh/check.c",
         "src/crypto/dh/dh.c",
         "src/crypto/dh/dh_asn1.c",
@@ -301,7 +300,6 @@
                 "linux-x86_64/crypto/fipsmodule/vpaes-x86_64.S",
                 "linux-x86_64/crypto/fipsmodule/x86_64-mont.S",
                 "linux-x86_64/crypto/fipsmodule/x86_64-mont5.S",
-                "src/crypto/curve25519/asm/x25519-asm-x86_64.S",
             ],
         },
     },
@@ -318,6 +316,7 @@
         "src/ssl/d1_srtp.cc",
         "src/ssl/dtls_method.cc",
         "src/ssl/dtls_record.cc",
+        "src/ssl/handoff.cc",
         "src/ssl/handshake.cc",
         "src/ssl/handshake_client.cc",
         "src/ssl/handshake_server.cc",