Adding ThreadChecker validation to d'tors for host classes

remoting/host/security_key/security_key_socket.cc

Index: remoting/host/security_key/security_key_socket.cc
diff --git a/remoting/host/security_key/security_key_socket.cc b/remoting/host/security_key/security_key_socket.cc
index 569e53cf12e4d9430e7fdfd8134d936ef5a6613e..bac15d6aa2a7366a124dcbd8e22cbcece4e4651e 100644
--- a/remoting/host/security_key/security_key_socket.cc
+++ b/remoting/host/security_key/security_key_socket.cc
@@ -35,7 +35,9 @@ SecurityKeySocket::SecurityKeySocket(std::unique_ptr<net::StreamSocket> socket,
   timer_->Start(FROM_HERE, timeout, timeout_callback);
 }
 
-SecurityKeySocket::~SecurityKeySocket() {}
+SecurityKeySocket::~SecurityKeySocket() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
 
 bool SecurityKeySocket::GetAndClearRequestData(std::string* data_out) {
   DCHECK(thread_checker_.CalledOnValidThread());