Revert "Fix protos_len size in SSL_set_alpn_protos and SSL_CTX_set_alpn_protos"

This reverts commit 35771ff8afc2201b5cf5b884db5b3889edde06bc. It breaks
tcnetty, which is tcnetty's fault but we have a large backlog from
Christmas to break with at the moment.

Bug: chromium:879657
Change-Id: Iafe93b335d88722170ec2689a25e145969e19e73
Reviewed-on: https://boringssl-review.googlesource.com/c/34324
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

include/openssl/ssl.h

diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h
index f09ffa4..59b9eac 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -2658,7 +2658,7 @@
 // WARNING: this function is dangerous because it breaks the usual return value
 // convention.
 OPENSSL_EXPORT int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
-                                           size_t protos_len);
+                                           unsigned protos_len);
 
 // SSL_set_alpn_protos sets the client ALPN protocol list on |ssl| to |protos|.
 // |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
@@ -2668,7 +2668,7 @@
 // WARNING: this function is dangerous because it breaks the usual return value
 // convention.
 OPENSSL_EXPORT int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos,
-                                       size_t protos_len);
+                                       unsigned protos_len);
 
 // SSL_CTX_set_alpn_select_cb sets a callback function on |ctx| that is called
 // during ClientHello processing in order to select an ALPN protocol from the

ssl/ssl_lib.cc

diff --git a/ssl/ssl_lib.cc b/ssl/ssl_lib.cc
index f3d92a6..bcf4bd2 100644
--- a/ssl/ssl_lib.cc
+++ b/ssl/ssl_lib.cc
@@ -2141,14 +2141,14 @@
 }
 
 int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
-                            size_t protos_len) {
+                            unsigned protos_len) {
   // Note this function's calling convention is backwards.
   return ctx->alpn_client_proto_list.CopyFrom(MakeConstSpan(protos, protos_len))
              ? 0
              : 1;
 }
 
-int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos, size_t protos_len) {
+int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos, unsigned protos_len) {
   // Note this function's calling convention is backwards.
   if (!ssl->config) {
     return 1;