Update net/third_party/nss to NSS 3.15.4.

net/third_party/nss/patches/versionskew.patch

-diff -pu a/nss/lib/ssl/sslsecur.c b/nss/lib/ssl/sslsecur.c
---- a/nss/lib/ssl/sslsecur.c    2013-07-31 12:07:10.974699609 -0700
-+++ b/nss/lib/ssl/sslsecur.c    2013-07-31 12:27:24.322323927 -0700
-@@ -1311,6 +1311,10 @@ SSL_SetURL(PRFileDesc *fd, const char *u
- SECStatus
- SSL_SetTrustAnchors(PRFileDesc *fd, CERTCertList *certList)
- {
-+    PORT_SetError(PR_NOT_IMPLEMENTED_ERROR);
-+    PR_NOT_REACHED("not implemented");
-+    return SECFailure;
-+#if 0
-     sslSocket *   ss = ssl_FindSocket(fd);
-     CERTDistNames *names = NULL;
- 
-@@ -1338,6 +1342,7 @@ SSL_SetTrustAnchors(PRFileDesc *fd, CERT
-     ssl_Release1stHandshakeLock(ss);
- 
-     return SECSuccess;
-+#endif
- }
- 
- /*
-diff -pu a/nss/lib/ssl/sslsock.c b/nss/lib/ssl/sslsock.c
---- a/nss/lib/ssl/sslsock.c     2013-07-31 12:07:10.974699609 -0700
-+++ b/nss/lib/ssl/sslsock.c     2013-07-31 12:27:24.322323927 -0700
-@@ -1625,6 +1625,11 @@ SSL_GetSRTPCipher(PRFileDesc *fd, PRUint
- PRFileDesc *
- SSL_ReconfigFD(PRFileDesc *model, PRFileDesc *fd)
- {
-+    PORT_SetError(PR_NOT_IMPLEMENTED_ERROR);
-+    PR_NOT_REACHED("not implemented");
-+    return NULL;
-+
-+#if 0
-     sslSocket * sm = NULL, *ss = NULL;
-     int i;
-     sslServerCerts * mc = NULL;
-@@ -1742,6 +1747,7 @@ SSL_ReconfigFD(PRFileDesc *model, PRFile
-     return fd;
- loser:
-     return NULL;
-+#endif
- }
- 
- PRBool