Convert reference counts in ssl/

Convert reference counts in ssl/ to use |CRYPTO_refcount_t|.

Change-Id: I5d60f641b0c89b1ddfe38bfbd9d7285c60377f4c
Reviewed-on: https://boringssl-review.googlesource.com/4773
Reviewed-by: Adam Langley <agl@google.com>

include/openssl/ssl.h

diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h
index 48b3fc0..6d1c29e 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -150,15 +150,13 @@
 #include <openssl/hmac.h>
 #include <openssl/lhash.h>
 #include <openssl/pem.h>
+#include <openssl/thread.h>
 #include <openssl/x509.h>
 
 #if !defined(OPENSSL_WINDOWS)
 #include <sys/time.h>
 #endif
 
-/* Some code expected to get the threading functions by including ssl.h. */
-#include <openssl/thread.h>
-
 /* wpa_supplicant expects to get the version functions from ssl.h */
 #include <openssl/crypto.h>
 
@@ -414,7 +412,7 @@
    * not ok, we must remember the error for session reuse: */
   long verify_result; /* only for servers */
 
-  int references;
+  CRYPTO_refcount_t references;
   long timeout;
   long time;
 
@@ -849,7 +847,7 @@
   SSL_SESSION *(*get_session_cb)(struct ssl_st *ssl, uint8_t *data, int len,
                                  int *copy);
 
-  int references;
+  CRYPTO_refcount_t references;
 
   /* if defined, these override the X509_verify_cert() calls */
   int (*app_verify_callback)(X509_STORE_CTX *, void *);