Supervised user blacklist: Don't download the blacklist file on every startup

chrome/browser/supervised_user/supervised_user_service.h

 // Copyright 2014 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_SUPERVISED_USER_SUPERVISED_USER_SERVICE_H_
 #define CHROME_BROWSER_SUPERVISED_USER_SUPERVISED_USER_SERVICE_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 263 matching lines @@
       size_t index,
       bool success);
 
   void OnSupervisedUserIdChanged();
 
   void OnDefaultFilteringBehaviorChanged();
 
   void OnSiteListsChanged(
       const std::vector<scoped_refptr<SupervisedUserSiteList>>& site_lists);
 
-  // Asynchronously downloads a static blacklist file from |url|, stores it at
-  // |path|, loads it, and applies it to the URL filters. If |url| is not valid
-  // (e.g. empty), directly tries to load from |path|.
+  // Asynchronously loads a blacklist from a binary file at |path| and applies
+  // it to the URL filters. If no file exists at |path| yet, downloads a file
+  // from |url| and stores it at |path| first.
   void LoadBlacklist(const base::FilePath& path, const GURL& url);
 
-  // Asynchronously loads a static blacklist from a binary file at |path| and
-  // applies it to the URL filters.
+  void OnBlacklistFileChecked(const base::FilePath& path,
+                              const GURL& url,
+                              bool file_exists);
+
+  // Asynchronously loads a blacklist from a binary file at |path| and applies
+  // it to the URL filters.
   void LoadBlacklistFromFile(const base::FilePath& path);
 
   void OnBlacklistDownloadDone(const base::FilePath& path, bool success);
 
   void OnBlacklistLoaded();
 
   // Updates the manual overrides for hosts in the URL filters when the
   // corresponding preference is changed.
   void UpdateManualHosts();
 
@@ skipping 45 matching lines @@
 
   // Used to create permission requests.
   ScopedVector<PermissionRequestCreator> permissions_creators_;
 
   ObserverList<SupervisedUserServiceObserver> observer_list_;
 
   base::WeakPtrFactory<SupervisedUserService> weak_ptr_factory_;
 };
 
 #endif  // CHROME_BROWSER_SUPERVISED_USER_SUPERVISED_USER_SERVICE_H_