Introduce a couple of abstract bases for WebDataService.

chrome/browser/webdata/autofill_web_data_service_impl.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 CHROME_BROWSER_WEBDATA_AUTOFILL_WEB_DATA_SERVICE_IMPL_H_
+#define CHROME_BROWSER_WEBDATA_AUTOFILL_WEB_DATA_SERVICE_IMPL_H_
+
+#include "base/memory/ref_counted.h"
+#include "chrome/browser/webdata/web_data_service.h"
+
+// This aggregates a WebDataService and delegates all method calls to
+// it.
+class AutofillWebDataServiceImpl : public AutofillWebDataService {

[dhollowa, 2012/09/07 16:04:01]

I find this name a bit confusing.  Mainly because the WebDataService is really
the "impl" and this class is more of a "bridge".  Maybe name this class
|AutofillWebDataServiceBridge|?

+ public:
+  AutofillWebDataServiceImpl(scoped_refptr<WebDataService> service);

[dhollowa, 2012/09/07 16:04:01]

nit: explicit

+
+  virtual WebDataServiceBase* NotificationSource() OVERRIDE;

[dhollowa, 2012/09/07 16:04:01]

// AutofillWebDataService implementation.

+
+  // AutofillWebData implementation.
+  virtual void AddFormFields(
+      const std::vector<webkit::forms::FormField>& fields) OVERRIDE;
+  virtual WebDataServiceBase::Handle GetFormValuesForElementName(
+      const string16& name,
+      const string16& prefix,
+      int limit,
+      WebDataServiceConsumer* consumer) OVERRIDE;
+  virtual void RemoveExpiredFormElements() OVERRIDE;
+  virtual void RemoveFormValueForElementName(const string16& name,
+                                             const string16& value) OVERRIDE;
+  virtual void AddAutofillProfile(const AutofillProfile& profile) OVERRIDE;
+  virtual void UpdateAutofillProfile(const AutofillProfile& profile) OVERRIDE;
+  virtual void RemoveAutofillProfile(const std::string& guid) OVERRIDE;
+  virtual WebDataServiceBase::Handle GetAutofillProfiles(
+      WebDataServiceConsumer* consumer) OVERRIDE;
+  virtual void EmptyMigrationTrash(bool notify_sync) OVERRIDE;
+  virtual void AddCreditCard(const CreditCard& credit_card) OVERRIDE;
+  virtual void UpdateCreditCard(const CreditCard& credit_card) OVERRIDE;
+  virtual void RemoveCreditCard(const std::string& guid) OVERRIDE;
+  virtual WebDataServiceBase::Handle
+      GetCreditCards(WebDataServiceConsumer* consumer) OVERRIDE;
+
+  // WebDataServiceBase implementation.
+  virtual void CancelRequest(Handle h) OVERRIDE;
+
+ private:
+  const scoped_refptr<WebDataService> service_;

[dhollowa, 2012/09/07 16:04:01]

How about |impl_|?

+};
+
+#endif  // CHROME_BROWSER_WEBDATA_AUTOFILL_WEB_DATA_SERVICE_IMPL_H_