Add support for GCM cipher suites from RFC 7714.

webrtc/api/peerconnection.cc

Index: webrtc/api/peerconnection.cc
diff --git a/webrtc/api/peerconnection.cc b/webrtc/api/peerconnection.cc
index 7f1f4523781685f062bfa0f7e8b639fd1cc1b8d4..61ff344cdcc614e7b80ddafa9aa8f53c4bd5d8aa 100644
--- a/webrtc/api/peerconnection.cc
+++ b/webrtc/api/peerconnection.cc
@@ -1503,6 +1503,7 @@ bool PeerConnection::GetOptionsForOffer(
   if (session_->data_channel_type() == cricket::DCT_SCTP && HasDataChannels()) {
     session_options->data_channel_type = cricket::DCT_SCTP;
   }
+  session_options->crypto_options = factory_->options().crypto_options;
   return true;
 }
 
@@ -1530,6 +1531,7 @@ void PeerConnection::FinishOptionsForAnswer(
   if (session_->data_channel_type() == cricket::DCT_SCTP) {
     session_options->data_channel_type = cricket::DCT_SCTP;
   }
+  session_options->crypto_options = factory_->options().crypto_options;
 }
 
 bool PeerConnection::GetOptionsForAnswer(