Introduced StoreKitTabHelper class

ios/chrome/browser/store_kit/store_kit_tab_helper.mm

+// Copyright 2017 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.
+
+#import "ios/chrome/browser/store_kit/store_kit_tab_helper.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+DEFINE_WEB_STATE_USER_DATA_KEY(StoreKitTabHelper);
+
+StoreKitTabHelper::StoreKitTabHelper(web::WebState* web_state) {}
+
+StoreKitTabHelper::~StoreKitTabHelper() {}
+
+void StoreKitTabHelper::SetLauncher(id<StoreKitLauncher> launcher) {
+  store_kit_launcher_.reset(launcher);
+}
+
+id<StoreKitLauncher> StoreKitTabHelper::GetLauncher() {
+  return store_kit_launcher_;
+}
+
+void StoreKitTabHelper::OpenAppStore(NSString* app_id) {
+  [store_kit_launcher_ openAppStore:app_id];
+}