Accept remote offers with current DTLS role, rather than "actpass".

webrtc/p2p/base/transportcontroller.cc

Index: webrtc/p2p/base/transportcontroller.cc
diff --git a/webrtc/p2p/base/transportcontroller.cc b/webrtc/p2p/base/transportcontroller.cc
index 3277ee970293135a6da94ba08feab4f22191ebda..f06a180088608301c7d73560a346b42383b69481 100644
--- a/webrtc/p2p/base/transportcontroller.cc
+++ b/webrtc/p2p/base/transportcontroller.cc
@@ -521,7 +521,11 @@ bool TransportController::GetSslRole_n(const std::string& transport_name,
   if (!t) {
     return false;
   }
-  t->GetSslRole(role);
+  rtc::Optional<rtc::SSLRole> current_role = t->GetSslRole();
+  if (!current_role) {
+    return false;
+  }
+  *role = *current_role;
   return true;
 }