Hook up Autofill Backend interface to SyncableServices

components/autofill/browser/webdata/autofill_webdata_backend.h

 #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 AutofillBackendDelegate;
 class AutofillChange;
 class AutofillProfile;
 class AutofillWebDataServiceObserverOnDBThread;
 class CreditCard;
 
 class AutofillWebDataBackend
     : public base::RefCountedThreadSafe<AutofillWebDataBackend,
           content::BrowserThread::DeleteOnDBThread> {
  public:
   AutofillWebDataBackend();
@@ skipping 23 matching lines @@
   WebDatabase::State RemoveCreditCardImpl(
       const std::string& guid, WebDatabase* db);
   scoped_ptr<WDTypedResult> GetCreditCardsImpl(WebDatabase* db);
   WebDatabase::State RemoveAutofillDataModifiedBetweenImpl(
       const base::Time& delete_begin, const base::Time& delete_end,
       WebDatabase* db);
 
   void AddObserver(AutofillWebDataServiceObserverOnDBThread* 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,
+      base::WeakPtr<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 (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_;
 
+  // All vended weak pointers are invalidated in dtor().

[erikwright (departed), 2013/04/25 19:06:10]

This comment is unnecessary (this is intrinsic in WeakPtrFactory).

+  base::WeakPtrFactory<AutofillWebDataBackend> weak_ptr_factory_;
+
+  // Delegate which allows clients to do autofill work directly on th DB thread.
+  // Owned by us.
+  scoped_ptr<AutofillBackendDelegate> delegate_;

[erikwright (departed), 2013/04/25 19:06:10]

Shouldn't the delegate be owned by whoever is using it? That's the point of the
WeakPtrs - the client can hold the delegate past the lifetime of the backend,
but at some point it will become a no-op.

Otherwise, instead of the delegate holding weakptrs to things it could hold raw
ptrs but the client holds a weak ptr to the delegate.

+
   DISALLOW_COPY_AND_ASSIGN(AutofillWebDataBackend);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_H_