Add support for GCM cipher suites from RFC 7714.

talk/session/media/channel.h

Index: talk/session/media/channel.h
diff --git a/talk/session/media/channel.h b/talk/session/media/channel.h
index 8faefe6d7b570c69185410237f04d68db28a5b8b..0e3f21492ad1a7f15386eae03a597ce37f4a2caf 100644
--- a/talk/session/media/channel.h
+++ b/talk/session/media/channel.h
@@ -174,6 +174,8 @@ class BaseChannel
 
   SrtpFilter* srtp_filter() { return &srtp_filter_; }
 
+  bool SetEnableGcmCryptoSuites(bool enable);
+
  protected:
   virtual MediaChannel* media_channel() const { return media_channel_; }
   // Sets the |transport_channel_| (and |rtcp_transport_channel_|, if |rtcp_| is
@@ -291,7 +293,8 @@ class BaseChannel
 
   // Handled in derived classes
   // Get the SRTP crypto suites to use for RTP media
-  virtual void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const = 0;
+  virtual void GetSrtpCryptoSuites(std::vector<int>* crypto_suites,
+      const MediaSessionOptions& options) const = 0;
   virtual void OnConnectionMonitorUpdate(ConnectionMonitor* monitor,
       const std::vector<ConnectionInfo>& infos) = 0;
 
@@ -329,6 +332,7 @@ class BaseChannel
   bool has_received_packet_;
   bool dtls_keyed_;
   bool secure_required_;
+  bool enable_gcm_crypto_suites_;
   int rtp_abs_sendtime_extn_id_;
 };
 
@@ -415,7 +419,8 @@ 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 MediaSessionOptions& options) const override;
   virtual void OnConnectionMonitorUpdate(
       ConnectionMonitor* monitor, const std::vector<ConnectionInfo>& infos);
   virtual void OnMediaMonitorUpdate(
@@ -505,7 +510,8 @@ class VideoChannel : public BaseChannel {
   bool GetStats_w(VideoMediaInfo* stats);
 
   virtual void OnMessage(rtc::Message* pmsg);
-  virtual void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const;
+  void GetSrtpCryptoSuites(std::vector<int>* crypto_suites,
+      const MediaSessionOptions& options) const override;
   virtual void OnConnectionMonitorUpdate(
       ConnectionMonitor* monitor, const std::vector<ConnectionInfo>& infos);
   virtual void OnMediaMonitorUpdate(
@@ -622,7 +628,8 @@ class DataChannel : public BaseChannel {
   virtual bool WantsPacket(bool rtcp, rtc::Buffer* packet);
 
   virtual void OnMessage(rtc::Message* pmsg);
-  virtual void GetSrtpCryptoSuites(std::vector<int>* crypto_suites) const;
+  void GetSrtpCryptoSuites(std::vector<int>* crypto_suites,
+      const MediaSessionOptions& options) const override;
   virtual void OnConnectionMonitorUpdate(
       ConnectionMonitor* monitor, const std::vector<ConnectionInfo>& infos);
   virtual void OnMediaMonitorUpdate(