Upstream dom_distiller iOS factories

ios/chrome/browser/dom_distiller/dom_distiller_service_factory.h

+// 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.
+
+#ifndef IOS_CHROME_BROWSER_DOM_DISTILLER_DOM_DISTILLER_SERVICE_FACTORY_H_
+#define IOS_CHROME_BROWSER_DOM_DISTILLER_DOM_DISTILLER_SERVICE_FACTORY_H_
+
+#include "components/dom_distiller/core/distilled_page_prefs.h"
+#include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
+
+template <typename T> struct DefaultSingletonTraits;
+
+class KeyedService;
+
+namespace dom_distiller {
+class DomDistillerService;
+}
+
+namespace web {
+class BrowserState;
+}
+
+namespace dom_distiller {
+
+class DomDistillerServiceFactory : public BrowserStateKeyedServiceFactory {
+ public:
+  static DomDistillerServiceFactory* GetInstance();
+  static DomDistillerService* GetForBrowserState(
+      web::BrowserState* browser_state);
+
+ private:
+  friend struct DefaultSingletonTraits<DomDistillerServiceFactory>;
+
+  DomDistillerServiceFactory();
+  ~DomDistillerServiceFactory() override;
+
+  // BrowserStateKeyedServiceFactory implementation.
+  KeyedService* BuildServiceInstanceFor(
+      web::BrowserState* browser_state) const override;
+  web::BrowserState* GetBrowserStateToUse(
+      web::BrowserState* browser_state) const override;
+};
+
+}  // namespace dom_distiller
+
+#endif  // IOS_CHROME_BROWSER_DOM_DISTILLER_DOM_DISTILLER_SERVICE_FACTORY_H_