Adding ThreadChecker validation to d'tors for protocol classes

remoting/protocol/ice_connection_to_client.cc

Index: remoting/protocol/ice_connection_to_client.cc
diff --git a/remoting/protocol/ice_connection_to_client.cc b/remoting/protocol/ice_connection_to_client.cc
index 90f9b1acdca011c67fafe942ad716feb1a7f84cf..6402e7c52ce0089decded7831cdc839e965a44c4 100644
--- a/remoting/protocol/ice_connection_to_client.cc
+++ b/remoting/protocol/ice_connection_to_client.cc
@@ -67,7 +67,9 @@ IceConnectionToClient::IceConnectionToClient(
   session_->SetTransport(&transport_);
 }
 
-IceConnectionToClient::~IceConnectionToClient() {}
+IceConnectionToClient::~IceConnectionToClient() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
 
 void IceConnectionToClient::SetEventHandler(
     ConnectionToClient::EventHandler* event_handler) {