Delete unused sigslot variables.

Bug: webrtc:11943
Change-Id: I55b9360de5188b1519aed184144f66d69763828c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/208240
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Lahiru Ginnaliya Gamathige <glahiru@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33328}
diff --git a/p2p/base/dtls_transport.cc b/p2p/base/dtls_transport.cc
index c37cd0f..8317bd2 100644
--- a/p2p/base/dtls_transport.cc
+++ b/p2p/base/dtls_transport.cc
@@ -816,7 +816,6 @@
   RTC_LOG(LS_VERBOSE) << ToString() << ": set_dtls_state from:" << dtls_state_
                       << " to " << state;
   dtls_state_ = state;
-  SignalDtlsState(this, state);
   SendDtlsState(this, state);
 }
 
diff --git a/p2p/base/dtls_transport_internal.h b/p2p/base/dtls_transport_internal.h
index 7771f1f..81aefa9 100644
--- a/p2p/base/dtls_transport_internal.h
+++ b/p2p/base/dtls_transport_internal.h
@@ -114,7 +114,6 @@
   // Expose the underneath IceTransport.
   virtual IceTransportInternal* ice_transport() = 0;
 
-  sigslot::signal2<DtlsTransportInternal*, DtlsTransportState> SignalDtlsState;
   // F: void(DtlsTransportInternal*, const DtlsTransportState)
   template <typename F>
   void SubscribeDtlsState(F&& callback) {
diff --git a/p2p/base/fake_dtls_transport.h b/p2p/base/fake_dtls_transport.h
index 9ab8998..f17eddf 100644
--- a/p2p/base/fake_dtls_transport.h
+++ b/p2p/base/fake_dtls_transport.h
@@ -85,7 +85,6 @@
   }
   void SetDtlsState(DtlsTransportState state) {
     dtls_state_ = state;
-    SignalDtlsState(this, dtls_state_);
     SendDtlsState(this, dtls_state_);
   }