Require explicit selection of traits for LazyInstance

ios/web/webui/web_ui_ios_controller_factory_registry.cc

 // Copyright 2014 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 "ios/web/webui/web_ui_ios_controller_factory_registry.h"
 
 #include <stddef.h>
 #include <memory>
 
 #include "base/lazy_instance.h"
 #include "ios/web/public/webui/web_ui_ios_controller.h"
 #include "url/gurl.h"
 #include "url/url_constants.h"
 
 namespace web {
 
-base::LazyInstance<std::vector<WebUIIOSControllerFactory*>> g_factories =
-    LAZY_INSTANCE_INITIALIZER;
+base::LazyInstance<std::vector<WebUIIOSControllerFactory*>>::DestructorAtExit
+    g_factories = LAZY_INSTANCE_INITIALIZER;
 
 void WebUIIOSControllerFactory::RegisterFactory(
     WebUIIOSControllerFactory* factory) {
   g_factories.Pointer()->push_back(factory);
 }
 
 WebUIIOSControllerFactoryRegistry*
 WebUIIOSControllerFactoryRegistry::GetInstance() {
   return base::Singleton<WebUIIOSControllerFactoryRegistry>::get();
 }
@@ skipping 11 matching lines @@
   return nullptr;
 }
 
 WebUIIOSControllerFactoryRegistry::WebUIIOSControllerFactoryRegistry() {
 }
 
 WebUIIOSControllerFactoryRegistry::~WebUIIOSControllerFactoryRegistry() {
 }
 
 }  // namespace web