[Upstream] Force instantiation of BSKSF during unit tests

ios/chrome/browser/browser_state/browser_state_keyed_service_factories.mm

+// Copyright 2015 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/chrome/browser/browser_state/browser_state_keyed_service_factories.h"
+
+#include "ios/chrome/browser/dom_distiller/dom_distiller_service_factory.h"
+#include "ios/chrome/browser/suggestions/suggestions_service_factory.h"
+#include "ios/chrome/browser/translate/translate_accept_languages_factory.h"
+
+// This method gets the instance of each ServiceFactory. We do this so that
+// each ServiceFactory initializes itself and registers its dependencies with
+// the global PreferenceDependencyManager. We need to have a complete
+// dependency graph when we create a browser state so we can dispatch the
+// browser state creation message to the services that want to create their
+// services at browser state creation time.
+//
+// TODO(erg): This needs to be something else. I don't think putting every
+// FooServiceFactory here will scale or is desirable long term.
+void EnsureBrowserStateKeyedServiceFactoriesBuilt() {
+  TranslateAcceptLanguagesFactory::GetInstance();
+  dom_distiller::DomDistillerServiceFactory::GetInstance();
+  suggestions::SuggestionsServiceFactory::GetInstance();
+}