[Reland] Refactor WebappRegistry into a singleton instance.

chrome/browser/browsing_data/browsing_data_remover.h

 // Copyright (c) 2012 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 CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_
 #define CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_
 
 #include <stdint.h>
 
 #include <queue>
@@ skipping 445 matching lines @@
 
 #if defined(ENABLE_WEBRTC)
   // Callback on UI thread when the WebRTC logs have been deleted.
   void OnClearedWebRtcLogs();
 #endif
 
 #if BUILDFLAG(ANDROID_JAVA_UI)
   // Callback on UI thread when the precache history has been cleared.
   void OnClearedPrecacheHistory();
 
-  // Callback on UI thread when the webapp data has been cleared.
-  void OnClearedWebappData();
-
-  // Callback on UI thread when the webapp history has been cleared.
-  void OnClearedWebappHistory();
-
   // Callback on UI thread when the offline page data has been cleared.
   void OnClearedOfflinePageData(
       offline_pages::OfflinePageModel::DeletePageResult result);
 #endif
 
   void OnClearedDomainReliabilityMonitor();
 
   // Returns true if we're all done.
   bool AllDone();
 
@@ skipping 56 matching lines @@
   bool waiting_for_clear_keyword_data_ = false;
   bool waiting_for_clear_nacl_cache_ = false;
   bool waiting_for_clear_network_predictor_ = false;
   bool waiting_for_clear_networking_history_ = false;
   bool waiting_for_clear_passwords_ = false;
   bool waiting_for_clear_passwords_stats_ = false;
   bool waiting_for_clear_platform_keys_ = false;
   bool waiting_for_clear_pnacl_cache_ = false;
 #if BUILDFLAG(ANDROID_JAVA_UI)
   bool waiting_for_clear_precache_history_ = false;
-  bool waiting_for_clear_webapp_data_ = false;
-  bool waiting_for_clear_webapp_history_ = false;
   bool waiting_for_clear_offline_page_data_ = false;
 #endif
   bool waiting_for_clear_storage_partition_data_ = false;
 #if defined(ENABLE_WEBRTC)
   bool waiting_for_clear_webrtc_logs_ = false;
 #endif
   bool waiting_for_clear_auto_sign_in_ = false;
 
   // Observers of the global state and individual tasks.
   base::ObserverList<Observer, true> observer_list_;
@@ skipping 11 matching lines @@
   // not initialised, so the registry must be mocked out.
   std::unique_ptr<WebappRegistry> webapp_registry_;
 #endif
 
   base::WeakPtrFactory<BrowsingDataRemover> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowsingDataRemover);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_