Create an AutofillBackend interface

components/autofill/browser/webdata/autofill_webdata_service.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_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_SERVICE_H_
 #define COMPONENTS_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_SERVICE_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/supports_user_data.h"
 #include "components/autofill/browser/webdata/autofill_webdata.h"
 #include "components/autofill/common/form_field_data.h"
 #include "components/webdata/common/web_data_results.h"
 #include "components/webdata/common/web_data_service_base.h"
 #include "components/webdata/common/web_data_service_consumer.h"
 #include "components/webdata/common/web_database.h"
 
 class WebDatabaseService;
 
 namespace content {
 class BrowserContext;
 }
 
 namespace autofill {
 
 class AutofillChange;
 class AutofillProfile;
 class AutofillWebDataBackend;
 class AutofillWebDataServiceObserverOnDBThread;
 class AutofillWebDataServiceObserverOnUIThread;
 class CreditCard;
+class SyncableServiceBackend;
 
 // API for Autofill web data.
 class AutofillWebDataService : public AutofillWebData,
                                public WebDataServiceBase {
  public:
   AutofillWebDataService();
 
   AutofillWebDataService(scoped_refptr<WebDatabaseService> wdbs,
                          const ProfileErrorCallback& callback);
 
@@ skipping 45 matching lines @@
 
   void AddObserver(AutofillWebDataServiceObserverOnUIThread* observer);
   void RemoveObserver(AutofillWebDataServiceObserverOnUIThread* observer);
 
   // Returns a SupportsUserData objects that may be used to store data
   // owned by the DB thread on this object. Should be called only from
   // the DB thread, and will be destroyed on the DB thread soon after
   // |ShutdownOnUIThread()| is called.
   base::SupportsUserData* GetDBUserData();
 
+  // Takes a callback which will be called on the DBThread with a pointer to a

[Ilya Sherman, 2013/05/08 00:39:06]

nit: "DBThread" -> "DB thread"; ditto below.

[Cait (Slow), 2013/05/08 19:16:01]

Done.

+  // |SyncableServiceBackend|. This backend can be used to access or update the
+  // WebDatabase directly on the DBThread.
+  void GetSyncableBackend(
+      const base::Callback<void(SyncableServiceBackend*)>& callback);

[Ilya Sherman, 2013/05/08 00:39:06]

Should this be returned as a scoped_refptr?  What's guaranteeing the lifetime of
the syncable backend for the client?

[Cait (Slow), 2013/05/08 19:16:01]

Both the backend and the syncable services are owned by the
AutofillWebDataService. The backend will outlive the syncable services as they
(the syncable services) get destroyed on the first pass of the shutdown process
(ShutdownOnUIThread) and the backend does not get destroyed until the second
pass (dtor). 

+
  protected:
   virtual ~AutofillWebDataService();
 
   virtual void ShutdownOnDBThread();
 
+  // This factory is used on the UIThread. All vended weak pointers are

[Ilya Sherman, 2013/05/08 00:39:06]

nit: "UIThread" -> "UI thread"

[Cait (Slow), 2013/05/08 19:16:01]

Done.

+  // invalidated in ShutdownOnUIThread().
+  base::WeakPtrFactory<AutofillWebDataService> weak_ptr_factory_;

[Ilya Sherman, 2013/05/08 00:39:06]

nit: Member variables should always have private visibility.

[Cait (Slow), 2013/05/08 19:16:01]

Done.

+
  private:
   // This makes the destructor public, and thus allows us to aggregate
   // SupportsUserData. It is private by default to prevent incorrect
   // usage in class hierarchies where it is inherited by
   // reference-counted objects.
   class SupportsUserDataAggregatable : public base::SupportsUserData {
    public:
     SupportsUserDataAggregatable() {}
     virtual ~SupportsUserDataAggregatable() {}
    private:
@@ skipping 10 matching lines @@
   ObserverList<AutofillWebDataServiceObserverOnUIThread> ui_observer_list_;
 
   scoped_refptr<AutofillWebDataBackend> autofill_backend_;
 
   DISALLOW_COPY_AND_ASSIGN(AutofillWebDataService);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_SERVICE_H_