Land https://codereview.chromium.org/889083003/ to update libsrtp to upstream 1.5.0

srtp/crypto/hash/hmac.c

 /*
  * hmac.c
  *
  * implementation of hmac auth_type_t
  *
  * David A. McGrew
  * Cisco Systems, Inc.
  */
 /*
  *      
@@ skipping 24 matching lines @@
  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
 
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
 #include "hmac.h" 
 #include "alloc.h"
 
 /* the debug module for authentiation */
 
 debug_module_t mod_hmac = {
   0,                  /* debugging is off by default */
   "hmac sha-1"        /* printable name for module   */
 };
 
@@ skipping 204 matching lines @@
   (auth_compute_func)    hmac_compute,
   (auth_update_func)     hmac_update,
   (auth_start_func)      hmac_start,
   (char *)               hmac_description,
   (int)                  0,  /* instance count */
   (auth_test_case_t *)  &hmac_test_case_0,
   (debug_module_t *)    &mod_hmac,
   (auth_type_id_t)       HMAC_SHA1
 };