Use Observer to notify of WebDB load instead of callbacks

components/webdata/common/web_data_service_base.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 COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BASE_H_
 #define COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BASE_H_
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/supports_user_data.h"
+#include "components/webdata/common/web_database_observer.h"
 #include "components/webdata/common/webdata_export.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_source.h"
 #include "sql/init_status.h"
 
 class WebDatabase;
 class WebDatabaseService;
 class WebDatabaseTable;
 
 namespace base {
 class Thread;
 }
 
 // Base for WebDataService class hierarchy.
 class WEBDATA_EXPORT WebDataServiceBase
-    : public base::RefCountedThreadSafe<WebDataServiceBase,
+    : public WebDatabaseObserver,
+      public base::RefCountedThreadSafe<WebDataServiceBase,
           content::BrowserThread::DeleteOnUIThread> {
  public:
   // All requests return an opaque handle of the following type.
   typedef int Handle;
 
   // Users of this class may provide a callback to handle errors
   // (e.g. by showing a UI). The callback is called only on error, and
   // takes a single parameter, the sql::InitStatus value from trying
   // to open the database.
   // TODO(joi): Should we combine this with WebDatabaseService::InitCallback?
   typedef base::Callback<void(sql::InitStatus)> ProfileErrorCallback;
 
   // |callback| will only be invoked on error, and only if
   // |callback.is_null()| evaluates to false.
   //
   // The ownership of |wdbs| is shared, with the primary owner being the
   // WebDataServiceWrapper, and secondary owners being subclasses of
   // WebDataServiceBase, which receive |wdbs| upon construction. The
   // WebDataServiceWrapper handles the initializing and shutting down and of
   // the |wdbs| object.
   WebDataServiceBase(scoped_refptr<WebDatabaseService> wdbs,
                      const ProfileErrorCallback& callback);
 
+  // WebDatabaseObserver implementation.
+  virtual void WebDatabaseLoaded() OVERRIDE;
+  virtual void WebDatabaseLoadFailed(sql::InitStatus status) OVERRIDE;
+
   // Cancel any pending request. You need to call this method if your
   // WebDataServiceConsumer is about to be deleted.
   virtual void CancelRequest(Handle h);
 
   // Returns the notification source for this service. This may use a
   // pointer other than this object's |this| pointer.
   virtual content::NotificationSource GetNotificationSource();
 
   // Shutdown the web data service. The service can no longer be used after this
   // call.
   virtual void ShutdownOnUIThread();
 
   // Initializes the web data service.
   virtual void Init();
 
   // Unloads the database without actually shutting down the service.  This can
   // be used to temporarily reduce the browser process' memory footprint.
   void UnloadDatabase();
 
   // Unloads the database permanently and shuts down service.
   void ShutdownDatabase();
 
+  virtual void AddDBObserver(WebDatabaseObserver* observer);
+  virtual void RemoveDBObserver(WebDatabaseObserver* observer);
+
   // Returns true if the database load has completetd successfully, and
   // ShutdownOnUIThread has not yet been called.
   virtual bool IsDatabaseLoaded();
 
   // Returns a pointer to the DB (used by SyncableServices). May return NULL if
   // the database is not loaded or otherwise unavailable. Must be called on
   // DBThread.
   virtual WebDatabase* GetDatabase();
 
   // Returns a SupportsUserData objects that may be used to store data
@@ skipping 31 matching lines @@
     SupportsUserDataAggregatable() {}
     virtual ~SupportsUserDataAggregatable() {}
    private:
     DISALLOW_COPY_AND_ASSIGN(SupportsUserDataAggregatable);
   };
 
   // Storage for user data to be accessed only on the DB thread. May
   // be used e.g. for SyncableService subclasses that need to be owned
   // by this object. Is created on first call to |GetDBUserData()|.
   scoped_ptr<SupportsUserDataAggregatable> db_thread_user_data_;
-
-  // Called after database is successfully loaded. By default this function does
-  // nothing. Subclasses can override to support notification.
-  virtual void NotifyDatabaseLoadedOnUIThread();
-
-  void DBInitFailed(sql::InitStatus sql_status);
-  void DBInitSucceeded();
-  void DatabaseInitOnDB(sql::InitStatus status);
 };
 
 #endif  // COMPONENTS_WEBDATA_COMMON_WEB_DATA_SERVICE_BASE_H_