Add LargeIconCache and LargeIconServiceFactory for iOS.

ios/chrome/browser/favicon/ios_chrome_large_icon_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_FAVICON_IOS_CHROME_LARGE_ICON_SERVICE_FACTORY_H_
+#define IOS_CHROME_BROWSER_FAVICON_IOS_CHROME_LARGE_ICON_SERVICE_FACTORY_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
+
+namespace base {
+template <typename T>
+struct DefaultSingletonTraits;
+class TaskRunner;
+}
+
+namespace ios {
+class ChromeBrowserState;
+}
+
+class KeyedService;
+
+namespace favicon {
+class LargeIconService;
+};
+
+// Singleton that owns all LargeIconService and associates them with
+// ChromeBrowserState.
+class IOSChromeLargeIconServiceFactory
+    : public BrowserStateKeyedServiceFactory {
+ public:
+  static favicon::LargeIconService* GetForBrowserState(
+      ios::ChromeBrowserState* browser_state);
+
+  static IOSChromeLargeIconServiceFactory* GetInstance();
+
+ private:
+  friend struct base::DefaultSingletonTraits<IOSChromeLargeIconServiceFactory>;
+
+  IOSChromeLargeIconServiceFactory();
+  ~IOSChromeLargeIconServiceFactory() override;
+
+  // BrowserStateKeyedServiceFactory implementation.
+  scoped_ptr<KeyedService> BuildServiceInstanceFor(
+      web::BrowserState* context) const override;
+  web::BrowserState* GetBrowserStateToUse(
+      web::BrowserState* context) const override;
+
+  DISALLOW_COPY_AND_ASSIGN(IOSChromeLargeIconServiceFactory);
+};
+
+#endif  // IOS_CHROME_BROWSER_FAVICON_IOS_CHROME_LARGE_ICON_SERVICE_FACTORY_H_