Add support for GCM cipher suites from RFC 7714.

webrtc/pc/channelmanager.cc

Index: webrtc/pc/channelmanager.cc
diff --git a/webrtc/pc/channelmanager.cc b/webrtc/pc/channelmanager.cc
index f59a3df9c72f7059e0c1a66aed639a66e2dbe518..86b6d31f55307235fe0b6be5e2b8420dd8130691 100644
--- a/webrtc/pc/channelmanager.cc
+++ b/webrtc/pc/channelmanager.cc
@@ -66,6 +66,7 @@ void ChannelManager::Construct(MediaEngineInterface* me,
   audio_output_volume_ = kNotSetOutputVolume;
   capturing_ = false;
   enable_rtx_ = false;
+  crypto_options_ = rtc::CryptoOptions::NoGcm();
 }
 
 ChannelManager::~ChannelManager() {
@@ -99,6 +100,22 @@ bool ChannelManager::SetVideoRtxEnabled(bool enable) {
   }
 }
 
+bool ChannelManager::SetCryptoOptions(
+    const rtc::CryptoOptions& crypto_options) {
+  return worker_thread_->Invoke<bool>(Bind(
+      &ChannelManager::SetCryptoOptions_w, this, crypto_options));
+}
+
+bool ChannelManager::SetCryptoOptions_w(
+    const rtc::CryptoOptions& crypto_options) {
+  if (!video_channels_.empty() || !voice_channels_.empty() ||
+      !data_channels_.empty()) {
+    LOG(LS_WARNING) << "Not changing crypto options in existing channels.";
+  }
+  crypto_options_ = crypto_options;
+  return true;
+}
+
 void ChannelManager::GetSupportedAudioCodecs(
     std::vector<AudioCodec>* codecs) const {
   codecs->clear();
@@ -230,6 +247,7 @@ VoiceChannel* ChannelManager::CreateVoiceChannel_w(
   VoiceChannel* voice_channel =
       new VoiceChannel(worker_thread_, media_engine_.get(), media_channel,
                        transport_controller, content_name, rtcp);
+  voice_channel->SetCryptoOptions(crypto_options_);
   if (!voice_channel->Init()) {
     delete voice_channel;
     return nullptr;
@@ -288,6 +306,7 @@ VideoChannel* ChannelManager::CreateVideoChannel_w(
 
   VideoChannel* video_channel = new VideoChannel(
       worker_thread_, media_channel, transport_controller, content_name, rtcp);
+  video_channel->SetCryptoOptions(crypto_options_);
   if (!video_channel->Init()) {
     delete video_channel;
     return NULL;
@@ -346,6 +365,7 @@ DataChannel* ChannelManager::CreateDataChannel_w(
 
   DataChannel* data_channel = new DataChannel(
       worker_thread_, media_channel, transport_controller, content_name, rtcp);
+  data_channel->SetCryptoOptions(crypto_options_);
   if (!data_channel->Init()) {
     LOG(LS_WARNING) << "Failed to init data channel.";
     delete data_channel;