Add support for GCM cipher suites from RFC 7714.

webrtc/pc/channel.h

Index: webrtc/pc/channel.h
diff --git a/webrtc/pc/channel.h b/webrtc/pc/channel.h
index 4518301d3b65e9e6fdf89586d258b519e42a4677..4268fd3add0cce6d97325090b54654ae826ecff6 100644
--- a/webrtc/pc/channel.h
+++ b/webrtc/pc/channel.h
@@ -158,6 +158,8 @@ class BaseChannel
 
   SrtpFilter* srtp_filter() { return &srtp_filter_; }
 
+  bool SetCryptoOptions(const rtc::CryptoOptions& crypto_options);
+
  protected:
   virtual MediaChannel* media_channel() const { return media_channel_; }
   // Sets the |transport_channel_| (and |rtcp_transport_channel_|, if |rtcp_| is
@@ -281,6 +283,10 @@ class BaseChannel
   // From MessageHandler
   void OnMessage(rtc::Message* pmsg) override;
 
+  const rtc::CryptoOptions& crypto_options() const {
+    return crypto_options_;
+  }
+
   // Handled in derived classes
   // Get the SRTP crypto suites to use for RTP media
   virtual void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const = 0;
@@ -321,6 +327,7 @@ class BaseChannel
   bool has_received_packet_;
   bool dtls_keyed_;
   bool secure_required_;
+  rtc::CryptoOptions crypto_options_;
   int rtp_abs_sendtime_extn_id_;
 };
 
@@ -411,7 +418,7 @@ class VoiceChannel : public BaseChannel {
   bool GetStats_w(VoiceMediaInfo* stats);
 
   virtual void OnMessage(rtc::Message* pmsg);
-  virtual void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const;
+  void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const override;
   virtual void OnConnectionMonitorUpdate(
       ConnectionMonitor* monitor, const std::vector<ConnectionInfo>& infos);
   virtual void OnMediaMonitorUpdate(
@@ -482,7 +489,7 @@ class VideoChannel : public BaseChannel {
   bool SetRtpParameters_w(uint32_t ssrc, webrtc::RtpParameters parameters);
 
   virtual void OnMessage(rtc::Message* pmsg);
-  virtual void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const;
+  void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const override;
   virtual void OnConnectionMonitorUpdate(
       ConnectionMonitor* monitor, const std::vector<ConnectionInfo>& infos);
   virtual void OnMediaMonitorUpdate(
@@ -592,7 +599,7 @@ class DataChannel : public BaseChannel {
   virtual bool WantsPacket(bool rtcp, const rtc::CopyOnWriteBuffer* packet);
 
   virtual void OnMessage(rtc::Message* pmsg);
-  virtual void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const;
+  void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const override;
   virtual void OnConnectionMonitorUpdate(
       ConnectionMonitor* monitor, const std::vector<ConnectionInfo>& infos);
   virtual void OnMediaMonitorUpdate(