Create an AutofillBackend interface

components/autofill/browser/webdata/autofill_webdata_backend.cc

Index: components/autofill/browser/webdata/autofill_webdata_backend.cc
diff --git a/components/autofill/browser/webdata/autofill_webdata_backend.cc b/components/autofill/browser/webdata/autofill_webdata_backend.cc
index 0cda3d15310d9e4796315c7be1d2442af50caffb..40e2d302b642620095578ed310f6a5c4fe2d9c8c 100644
--- a/components/autofill/browser/webdata/autofill_webdata_backend.cc
+++ b/components/autofill/browser/webdata/autofill_webdata_backend.cc
@@ -12,7 +12,9 @@
 #include "components/autofill/browser/webdata/autofill_change.h"
 #include "components/autofill/browser/webdata/autofill_entry.h"
 #include "components/autofill/browser/webdata/autofill_table.h"
+#include "components/autofill/browser/webdata/autofill_webdata_service.h"
 #include "components/autofill/browser/webdata/autofill_webdata_service_observer.h"
+#include "components/autofill/browser/webdata/syncable_service_delegate.h"
 #include "components/autofill/common/form_field_data.h"
 
 using base::Bind;
@@ -21,6 +23,71 @@ using content::BrowserThread;
 
 namespace autofill {
 
+class SyncableAutofillDelegate : public SyncableServiceDelegate {

[Jói, 2013/05/06 23:08:39]

Do you expect that there might be multiple implementations of
SyncableServiceDelegate? If not (and maybe even if), it doesn't really seem like
a delegate to me... more like an interface implemented by AutofillWebDataService
and possibly other services - in which case maybe it should be called
SyncableServiceDatabase or some such?

+ public:
+  SyncableAutofillDelegate(
+    WebDatabase* db,
+    AutofillWebDataBackend* autofill_backend,
+    const base::Closure& on_changed)
+    : web_database_(db),
+      autofill_backend_(autofill_backend),
+      on_changed_(new base::Closure(on_changed)),
+      weak_ptr_factory_(this) {
+  }
+
+  virtual ~SyncableAutofillDelegate() {
+  }
+
+  base::WeakPtr<SyncableAutofillDelegate> AsWeakPtr() {
+    return weak_ptr_factory_.GetWeakPtr();
+  }
+
+  virtual WebDatabase* GetDatabase() OVERRIDE {
+    return web_database_;
+  }
+
+  virtual void AddObserver(
+      AutofillWebDataServiceObserverOnDBThread* observer) OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
+    if (autofill_backend_)
+      autofill_backend_->AddObserver(observer);
+  }
+
+  virtual void RemoveObserver(
+    AutofillWebDataServiceObserverOnDBThread* observer) OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
+    if (autofill_backend_)
+      autofill_backend_->RemoveObserver(observer);
+  }
+
+  virtual void RemoveExpiredFormElements() OVERRIDE {
+    if (!autofill_backend_)
+      return;
+
+    WebDatabase::State state =
+        autofill_backend_->RemoveExpiredFormElements(web_database_);
+
+    if (state == WebDatabase::COMMIT_NEEDED) {
+      web_database_->CommitTransaction();
+      web_database_->BeginTransaction();
+    }
+  }
+
+  virtual void NotifyOfMultipleAutofillChanges() OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
+
+    if (!autofill_backend_ || !on_changed_ || on_changed_->is_null())
+      return;
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, *on_changed_);
+  }
+
+ private:
+  WebDatabase* web_database_;
+  AutofillWebDataBackend* autofill_backend_;
+  base::Closure* on_changed_;
+  base::WeakPtrFactory<SyncableAutofillDelegate> weak_ptr_factory_;
+};

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

nit: Please tuck this into an anonymous namespace.

+
 AutofillWebDataBackend::AutofillWebDataBackend() {
 }
 
@@ -36,7 +103,19 @@ void AutofillWebDataBackend::RemoveObserver(
   db_observer_list_.RemoveObserver(observer);
 }
 
+void AutofillWebDataBackend::GetDelegate(
+  const AutofillWebDataService::DelegateOnDBCallback& callback,
+  const base::Closure& on_changed_callback,
+  WebDatabase* db) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
+  if (!delegate_.get())
+    delegate_.reset(new SyncableAutofillDelegate(
+        db, this, on_changed_callback));
+  callback.Run(delegate_->AsWeakPtr());
+}
+
 AutofillWebDataBackend::~AutofillWebDataBackend() {
+  delegate_.reset();
 }
 
 WebDatabase::State AutofillWebDataBackend::AddFormElements(