Enable AES_256_GCM ciphers.

net/ssl/ssl_config.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_SSL_SSL_CONFIG_H_
 #define NET_SSL_SSL_CONFIG_H_
 
 #include <stdint.h>
 
 #include "base/memory/ref_counted.h"
@@ skipping 79 matching lines @@
 
   // version_fallback_min contains the minimum version that is acceptable to
   // fallback to. Versions before this may be tried to see whether they would
   // have succeeded and thus to give a better message to the user, but the
   // resulting connection won't be used in these cases.
   uint16_t version_fallback_min;
 
   // Presorted list of cipher suites which should be explicitly prevented from
   // being used in addition to those disabled by the net built-in policy.
   //
-  // By default, all cipher suites supported by the underlying SSL
-  // implementation will be enabled except for:

[davidben, 2016/03/08 01:42:16]

This comment isn't terribly meaningful anymore since BoringSSL doesn't implement
most of this to begin with.

-  // - Null encryption cipher suites.
-  // - Weak cipher suites: < 80 bits of security strength.
-  // - FORTEZZA cipher suites (obsolete).
-  // - IDEA cipher suites (RFC 5469 explains why).
-  // - Anonymous cipher suites.
-  // - ECDSA cipher suites on platforms that do not support ECDSA signed
-  //   certificates, as servers may use the presence of such ciphersuites as a
-  //   hint to send an ECDSA certificate.
-  // The ciphers listed in |disabled_cipher_suites| will be removed in addition
-  // to the above list.
-  //
   // Though cipher suites are sent in TLS as "uint8_t CipherSuite[2]", in
   // big-endian form, they should be declared in host byte order, with the
   // first uint8_t occupying the most significant byte.
   // Ex: To disable TLS_RSA_WITH_RC4_128_MD5, specify 0x0004, while to
   // disable TLS_ECDH_ECDSA_WITH_RC4_128_SHA, specify 0xC002.
   std::vector<uint16_t> disabled_cipher_suites;
 
   // Enables deprecated cipher suites. These cipher suites are selected under a
   // fallback to distinguish servers which require them from servers which
   // merely prefer them.
@@ skipping 76 matching lines @@
   // The list of application-level protocols to enable renegotiation for.
   NextProtoVector renego_allowed_for_protos;
 
   scoped_refptr<X509Certificate> client_cert;
   scoped_refptr<SSLPrivateKey> client_private_key;
 };
 
 }  // namespace net
 
 #endif  // NET_SSL_SSL_CONFIG_H_