Enforce singleton not allowed behavior for CONTINUE_ON_SHUTDOWN tasks

net/proxy/dhcpcsvc_init_win.cc

Index: net/proxy/dhcpcsvc_init_win.cc
diff --git a/net/proxy/dhcpcsvc_init_win.cc b/net/proxy/dhcpcsvc_init_win.cc
index 7e32aeae9cd5593b3d788341cdd5bc9f8d845ece..d243f1859aa3a3f446548e25a4eb9581d044e08f 100644
--- a/net/proxy/dhcpcsvc_init_win.cc
+++ b/net/proxy/dhcpcsvc_init_win.cc
@@ -19,15 +19,12 @@ class DhcpcsvcInitSingleton {
     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