webrtc/base: Use RTC_DCHECK() instead of assert()

Review-Url: https://codereview.webrtc.org/2325623002
Cr-Commit-Position: refs/heads/master@{#14192}
diff --git a/webrtc/base/firewallsocketserver.cc b/webrtc/base/firewallsocketserver.cc
index bf3ec42..d6d03df 100644
--- a/webrtc/base/firewallsocketserver.cc
+++ b/webrtc/base/firewallsocketserver.cc
@@ -10,11 +10,10 @@
 
 #include "webrtc/base/firewallsocketserver.h"
 
-#include <assert.h>
-
 #include <algorithm>
 
 #include "webrtc/base/asyncsocket.h"
+#include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 
 namespace rtc {
@@ -220,7 +219,7 @@
 }
 
 FirewallManager::~FirewallManager() {
-  assert(servers_.empty());
+  RTC_DCHECK(servers_.empty());
 }
 
 void FirewallManager::AddServer(FirewallSocketServer* server) {