Gracefully handle NULL CertVerifiers in SSLClientSocket.

net/socket/ssl_client_socket_nss.cc

Index: net/socket/ssl_client_socket_nss.cc
diff --git a/net/socket/ssl_client_socket_nss.cc b/net/socket/ssl_client_socket_nss.cc
index 16641f9894477e09bbbccd092f99ce8e01fed384..7e27565c7aa9100302d17ec4a2076bc84fcb8f22 100644
--- a/net/socket/ssl_client_socket_nss.cc
+++ b/net/socket/ssl_client_socket_nss.cc
@@ -3091,6 +3091,12 @@ int SSLClientSocketNSS::DoVerifyCert(int result) {
     return ERR_CERT_INVALID;
   }
 
+  if (!cert_verifier_) {
+    // Without a CertVerifier, all certificates are invalid.
+    server_cert_verify_result_.cert_status = CERT_STATUS_INVALID;
+    return ERR_CERT_INVALID;
+  }
+
   start_cert_verification_time_ = base::TimeTicks::Now();
 
   int flags = 0;