Add support for GCM cipher suites from RFC 7714.

webrtc/api/peerconnectionfactory.cc

Index: webrtc/api/peerconnectionfactory.cc
diff --git a/webrtc/api/peerconnectionfactory.cc b/webrtc/api/peerconnectionfactory.cc
index ff8098cd57a277235a9cd72e01823503c740efda..19d93ec5b60fd6433fe23735b3e1ffe53fce1eaa 100644
--- a/webrtc/api/peerconnectionfactory.cc
+++ b/webrtc/api/peerconnectionfactory.cc
@@ -176,6 +176,7 @@ bool PeerConnectionFactory::Initialize() {
       new cricket::ChannelManager(media_engine, worker_thread_));
 
   channel_manager_->SetVideoRtxEnabled(true);
+  channel_manager_->SetCryptoOptions(options_.crypto_options);
   if (!channel_manager_->Init()) {
     return false;
   }
@@ -186,6 +187,13 @@ bool PeerConnectionFactory::Initialize() {
   return true;
 }
 
+void PeerConnectionFactory::SetOptions(const Options& options) {
+  options_ = options;
+  if (channel_manager_) {
+    channel_manager_->SetCryptoOptions(options.crypto_options);
+  }
+}
+
 rtc::scoped_refptr<AudioSourceInterface>
 PeerConnectionFactory::CreateAudioSource(
     const MediaConstraintsInterface* constraints) {