Implement TLS_FALLBACK_SCSV for SSLClientSocketOpenSSL.

net/socket/openssl_ssl_util.cc

Index: net/socket/openssl_ssl_util.cc
diff --git a/net/socket/openssl_ssl_util.cc b/net/socket/openssl_ssl_util.cc
index 231f77cceacb77134a574cd2fba5581bb7a69f96..f4e3884fc32b8f8cc6f6acdcfb71b4fb96878401 100644
--- a/net/socket/openssl_ssl_util.cc
+++ b/net/socket/openssl_ssl_util.cc
@@ -148,6 +148,8 @@ int MapOpenSSLErrorSSL(unsigned long error_code) {
       // The only way that the certificate verify callback can fail is if
       // the leaf certificate changed during a renegotiation.
       return ERR_SSL_SERVER_CERT_CHANGED;
+    case SSL_AD_REASON_OFFSET + SSL3_AD_INAPPROPRIATE_FALLBACK:
+      return ERR_SSL_INAPPROPRIATE_FALLBACK;
     default:
       LOG(WARNING) << "Unmapped error reason: " << ERR_GET_REASON(error_code);
       return ERR_FAILED;