Hook up Autofill Backend interface to SyncableServices

components/autofill/browser/webdata/autofill_webdata_backend.h

Index: components/autofill/browser/webdata/autofill_webdata_backend.h
diff --git a/components/autofill/browser/webdata/autofill_webdata_backend.h b/components/autofill/browser/webdata/autofill_webdata_backend.h
index dcfa63595ab1368489acb613bd90e83b3ee5b496..b234260ca7c51becffabec5096f31544e656ea53 100644
--- a/components/autofill/browser/webdata/autofill_webdata_backend.h
+++ b/components/autofill/browser/webdata/autofill_webdata_backend.h
@@ -2,8 +2,10 @@
 #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"
@@ -12,6 +14,7 @@
 
 namespace autofill {
 
+class AutofillBackendDelegate;
 class AutofillChange;
 class AutofillProfile;
 class AutofillWebDataServiceObserverOnDBThread;
@@ -55,6 +58,12 @@ class AutofillWebDataBackend
   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();
 
@@ -73,6 +82,13 @@ class AutofillWebDataBackend
 
   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);
 };