SafeBrowsing: Move enabled_ to base class DB Manager

components/safe_browsing_db/database_manager.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.
 //
 // The Safe Browsing service is responsible for downloading anti-phishing and
 // anti-malware tables and checking urls against them.
 
 #ifndef COMPONENTS_SAFE_BROWSING_DB_DATABASE_MANAGER_H_
 #define COMPONENTS_SAFE_BROWSING_DB_DATABASE_MANAGER_H_
 
@@ skipping 178 matching lines @@
   // If false, calls to CheckBrowseUrl may dcheck-fail.
   virtual bool IsSupported() const = 0;
 
   //
   // Methods to indicate when to start or suspend the SafeBrowsing operations.
   // These functions are always called on the IO thread.
   //
 
   // Called to initialize objects that are used on the io_thread, such as the
   // v4 protocol manager.  This may be called multiple times during the life of
-  // the DatabaseManager. Must be called on IO thread.
+  // the DatabaseManager. Must be called on IO thread. All subclasses should
+  // override this method, set enabled_ to true and call the base class method
+  // at the top of it.
   virtual void StartOnIOThread(
       net::URLRequestContextGetter* request_context_getter,
       const V4ProtocolConfig& config);
 
-  // Called to stop or shutdown operations on the io_thread.
+  // Called to stop or shutdown operations on the io_thread. All subclasses
+  // should override this method, set enabled_ to false and call the base class
+  // method at the bottom of it.
   virtual void StopOnIOThread(bool shutdown);
 
  protected:
   // Bundled client info for an API abuse hash prefix check.
   class SafeBrowsingApiCheck {
    public:
     SafeBrowsingApiCheck(const GURL& url, Client* client);
     ~SafeBrowsingApiCheck();
 
     const GURL& url() const { return url_; }
@@ skipping 40 matching lines @@
   // CheckApiBlacklistUrl.
   void OnThreatMetadataResponse(std::unique_ptr<SafeBrowsingApiCheck> check,
                                 const ThreatMetadata& md);
 
   typedef std::set<SafeBrowsingApiCheck*> ApiCheckSet;
 
   // In-progress checks. This set owns the SafeBrowsingApiCheck pointers and is
   // responsible for deleting them when removing from the set.
   ApiCheckSet api_checks_;
 
+  // Whether the service is running. 'enabled_' is used by the
+  // SafeBrowsingDatabaseManager on the IO thread during normal operations.
+  bool enabled_;
+
   // Created and destroyed via StartOnIOThread/StopOnIOThread.
   std::unique_ptr<V4GetHashProtocolManager> v4_get_hash_protocol_manager_;
 
  private:
   // Returns an iterator to the pending API check with the given |client|.
   ApiCheckSet::iterator FindClientApiCheck(Client* client);
 };  // class SafeBrowsingDatabaseManager
 
 }  // namespace safe_browsing
 
 #endif  // COMPONENTS_SAFE_BROWSING_DB_DATABASE_MANAGER_H_