Create an AutofillBackend interface

components/autofill/browser/webdata/autofill_webdata_backend.h

 // Copyright 2013 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_BACKEND_H_
 #define COMPONENTS_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_H_
 
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "components/autofill/browser/webdata/autofill_webdata.h"
+#include "components/autofill/browser/webdata/autofill_webdata_service.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"
 
 namespace autofill {
 
 class AutofillChange;
 class AutofillProfile;
 class AutofillWebDataServiceObserverOnDBThread;
 class CreditCard;
+class SyncableAutofillDelegate;
 
 // Backend implentation for the AutofillWebDataService. This class runs on the
 // DB thread, as it handles reads and writes to the WebDatabase, and functions
 // in it should only be called from that thread. Most functions here are just
 // the implementations of the corresponding functions in the Autofill
 // WebDataService.
 class AutofillWebDataBackend
     : public base::RefCountedThreadSafe<AutofillWebDataBackend,
           content::BrowserThread::DeleteOnDBThread> {
  public:
@@ skipping 61 matching lines @@
       const base::Time& delete_begin,
       const base::Time& delete_end,
       WebDatabase* db);
 
   // Add an observer to be notified of changes on the DB thread.
   void AddObserver(AutofillWebDataServiceObserverOnDBThread* observer);
 
   // Remove an observer.
   void RemoveObserver(AutofillWebDataServiceObserverOnDBThread* observer);
 
+  // Initializes |delegate_| if it has not already been initialized, and returns
+  // a ptr to it asynchonously via |callback|.
+  void GetDelegate(
+      const AutofillWebDataService::DelegateOnDBCallback& callback,
+      const base::Closure& on_changed_callback,

[Ilya Sherman, 2013/05/07 00:02:43]

nit: Docs for this param

+      WebDatabase* db);
+
  protected:
   virtual ~AutofillWebDataBackend();
 
  private:
   friend struct content::BrowserThread::DeleteOnThread<
       content::BrowserThread::DB>;
   friend class base::DeleteHelper<AutofillWebDataBackend>;
   // We have to friend RCTS<> so WIN shared-lib build is happy
   // (http://crbug/112250).
   friend class base::RefCountedThreadSafe<AutofillWebDataBackend,
       content::BrowserThread::DeleteOnDBThread>;
 
   // Callbacks to ensure that sensitive info is destroyed if request is
   // cancelled.
   void DestroyAutofillProfileResult(const WDTypedResult* result);
   void DestroyAutofillCreditCardResult(const WDTypedResult* result);
 
   ObserverList<AutofillWebDataServiceObserverOnDBThread> db_observer_list_;
 
+  // Delegate which allows clients to do autofill work directly on th DB thread.
+  // Owned by us.
+  scoped_ptr<SyncableAutofillDelegate> delegate_;
+
   DISALLOW_COPY_AND_ASSIGN(AutofillWebDataBackend);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_H_