Enforce singleton not allowed behavior for CONTINUE_ON_SHUTDOWN tasks

net/proxy/dhcpcsvc_init_win.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/proxy/dhcpcsvc_init_win.h"
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 
 #include <dhcpcsdk.h>
 #include <dhcpv6csdk.h>
 
 namespace {
 
 class DhcpcsvcInitSingleton {
  public:
   DhcpcsvcInitSingleton() {
     DWORD version = 0;
     DWORD err = DhcpCApiInitialize(&version);
     DCHECK(err == ERROR_SUCCESS);  // DCHECK_EQ complains of unsigned mismatch.
   }
-
-  ~DhcpcsvcInitSingleton() {
-    // Worker pool threads that use the DHCP API may still be running, so skip
-    // cleanup.
-  }
 };
 
-static base::LazyInstance<DhcpcsvcInitSingleton> g_dhcpcsvc_init_singleton =
-    LAZY_INSTANCE_INITIALIZER;
+// Worker pool threads that use the DHCP API may still be running at shutdown.
+// Leak instance and skip cleanup.
+static base::LazyInstance<DhcpcsvcInitSingleton>::Leaky
+    g_dhcpcsvc_init_singleton = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 namespace net {
 
 void EnsureDhcpcsvcInit() {
   g_dhcpcsvc_init_singleton.Get();
 }
 
 }  // namespace net