Add support for GCM cipher suites from RFC 7714.

webrtc/p2p/base/transportcontroller.h

Index: webrtc/p2p/base/transportcontroller.h
diff --git a/webrtc/p2p/base/transportcontroller.h b/webrtc/p2p/base/transportcontroller.h
index 8d57b460e80c001821dda6cec6e7ae0c2d3c0d85..3267414208cc33f8361faed36a92bdad68ae4345 100644
--- a/webrtc/p2p/base/transportcontroller.h
+++ b/webrtc/p2p/base/transportcontroller.h
@@ -44,6 +44,7 @@ class TransportController : public sigslot::has_slots<>,
   // TODO(deadbeef): Make this an argument to the constructor once BaseSession
   // and WebRtcSession are combined
   bool SetSslMaxProtocolVersion(rtc::SSLProtocolVersion version);
+  bool SetEnableGcmCiphers(bool enable);
 
   void SetIceConfig(const IceConfig& config);
   void SetIceRole(IceRole ice_role);
@@ -158,6 +159,7 @@ class TransportController : public sigslot::has_slots<>,
   void DestroyAllTransports_w();
 
   bool SetSslMaxProtocolVersion_w(rtc::SSLProtocolVersion version);
+  bool SetEnableGcmCiphers_w(bool enable);
   void SetIceConfig_w(const IceConfig& config);
   void SetIceRole_w(IceRole ice_role);
   bool GetSslRole_w(rtc::SSLRole* role);
@@ -203,6 +205,7 @@ class TransportController : public sigslot::has_slots<>,
 
   PortAllocator* const port_allocator_ = nullptr;
   rtc::SSLProtocolVersion ssl_max_version_ = rtc::SSL_PROTOCOL_DTLS_10;
+  bool enable_gcm_ciphers_ = false;
 
   // Aggregate state for TransportChannelImpls.
   IceConnectionState connection_state_ = kIceConnectionConnecting;