[Icons NTP] Refactor large_icon_source to extract the logic shared between desktop and Android to f…

chrome/browser/favicon/large_icon_service_factory.h

+// Copyright 2015 The Chromium Authors. All rights reserved.

[huangs, 2015/04/20 19:50:25]

I presume this file was branched from a sibling file. On your next upload,
please set

git cl upload --similarity=20

(or some thing)
so we better see diffs.

[beaudoin, 2015/04/21 00:15:38]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_FAVICON_LARGE_ICON_SERVICE_FACTORY_H_
+#define CHROME_BROWSER_FAVICON_LARGE_ICON_SERVICE_FACTORY_H_
+
+#include "components/keyed_service/content/browser_context_keyed_service_factory.h"
+
+template <typename T> struct DefaultSingletonTraits;
+
+namespace content {
+class BrowserContext;
+}
+
+namespace favicon {
+class LargeIconService;
+}
+
+// Singleton that owns all LargeIconService and associates them with
+// BrowserContext instances.
+class LargeIconServiceFactory : public BrowserContextKeyedServiceFactory {
+ public:
+  static favicon::LargeIconService* GetForBrowserContext(
+      content::BrowserContext* context);
+
+  static LargeIconServiceFactory* GetInstance();
+
+ private:
+  friend struct DefaultSingletonTraits<LargeIconServiceFactory>;
+
+  LargeIconServiceFactory();
+  ~LargeIconServiceFactory() override;
+
+  // BrowserContextKeyedServiceFactory:
+  KeyedService* BuildServiceInstanceFor(
+      content::BrowserContext* context) const override;
+  bool ServiceIsNULLWhileTesting() const override;
+
+  DISALLOW_COPY_AND_ASSIGN(LargeIconServiceFactory);
+};
+
+#endif  // CHROME_BROWSER_FAVICON_LARGE_ICON_SERVICE_FACTORY_H_