Abstract content::BrowserThread usage out of AutofillWebDataBackendImpl.

components/autofill/core/browser/webdata/autofill_webdata_backend_impl.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_CORE_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_IMPL_H_
 #define COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_IMPL_H_
 
 #include "base/memory/ref_counted.h"
+#include "base/memory/ref_counted_delete_on_message_loop.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop_proxy.h"

[Ilya Sherman, 2013/10/02 23:27:01]

nit: Seems like this could just be forward-declared.

[blundell, 2013/10/03 05:23:34]

Done.

 #include "base/observer_list.h"
 #include "base/supports_user_data.h"
 #include "components/autofill/core/browser/webdata/autofill_webdata.h"
 #include "components/autofill/core/browser/webdata/autofill_webdata_backend.h"
 #include "components/autofill/core/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"
-#include "content/public/browser/browser_thread.h"
 
 class WebDataServiceBackend;
 
 namespace autofill {
 
 class AutofillChange;
 class AutofillProfile;
 class AutofillWebDataServiceObserverOnDBThread;
 class CreditCard;
 
 // 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.
+// This class is destroyed on the DB thread.
 class AutofillWebDataBackendImpl
-    : public base::RefCountedThreadSafe<AutofillWebDataBackendImpl,
-          content::BrowserThread::DeleteOnDBThread>,
+    : public base::RefCountedDeleteOnMessageLoop<AutofillWebDataBackendImpl>,
       public AutofillWebDataBackend {
  public:
   // |web_database_backend| is used to access the WebDatabase directly for
-  // Sync-related operations. |on_changed_callback| is a closure which can be
-  // used to notify the UI thread of changes initiated by Sync (this callback
-  // may be called multiple times).
+  // Sync-related operations. |ui_thread| and |db_thread| are the threads that
+  // this class uses as its UI and DB threads respectively.
+  // |on_changed_callback| is a closure which can be used to notify the UI
+  // thread of changes initiated by Sync (this callback may be called multiple
+  // times).
   AutofillWebDataBackendImpl(
       scoped_refptr<WebDataServiceBackend> web_database_backend,
+      const scoped_refptr<base::MessageLoopProxy>& ui_thread,
+      const scoped_refptr<base::MessageLoopProxy>& db_thread,

[Ilya Sherman, 2013/10/02 23:27:01]

Hmm, should scoped_refptrs really be passed by const-reference?  The one above
is just passed by value, which seems potentially more appropriate.

[blundell, 2013/10/03 05:23:34]

Looking through the codebase, both get used. I'll change these for local
consistency and will consider posting the question on chromium-dev@.

On 2013/10/02 23:27:01, Ilya Sherman wrote:

       const base::Closure& on_changed_callback);
 
   // AutofillWebDataBackend implementation.
   virtual void AddObserver(AutofillWebDataServiceObserverOnDBThread* observer)
       OVERRIDE;
   virtual void RemoveObserver(
       AutofillWebDataServiceObserverOnDBThread* observer) OVERRIDE;
   virtual WebDatabase* GetDatabase() OVERRIDE;
   virtual void RemoveExpiredFormElements() OVERRIDE;
   virtual void NotifyOfMultipleAutofillChanges() OVERRIDE;
@@ skipping 74 matching lines @@
   // the database.
   WebDatabase::State RemoveOriginURLsModifiedBetween(
       const base::Time& delete_begin,
       const base::Time& delete_end,
       WebDatabase* db);
 
  protected:
   virtual ~AutofillWebDataBackendImpl();
 
  private:
-  friend struct content::BrowserThread::DeleteOnThread<
-      content::BrowserThread::DB>;
+  friend class base::RefCountedDeleteOnMessageLoop<AutofillWebDataBackendImpl>;
   friend class base::DeleteHelper<AutofillWebDataBackendImpl>;
-  // We have to friend RCTS<> so WIN shared-lib build is happy
-  // (http://crbug/112250).
-  friend class base::RefCountedThreadSafe<AutofillWebDataBackendImpl,
-      content::BrowserThread::DeleteOnDBThread>;
 
   // This makes the destructor public, and thus allows us to aggregate
   // SupportsUserData. It is private by default to prevent incorrect
   // usage in class hierarchies where it is inherited by
   // reference-counted objects.
   class SupportsUserDataAggregatable : public base::SupportsUserData {
    public:
     SupportsUserDataAggregatable() {}
     virtual ~SupportsUserDataAggregatable() {}
    private:
     DISALLOW_COPY_AND_ASSIGN(SupportsUserDataAggregatable);
   };
 
+  // The MessageLoopProxy that this class uses as its UI thread.
+  scoped_refptr<base::MessageLoopProxy> ui_thread_;
+
+  // The MessageLoopProxy that this class uses as its DB thread.
+  scoped_refptr<base::MessageLoopProxy> db_thread_;
+
   // Storage for user data to be accessed only on the DB thread. May
   // be used e.g. for SyncableService subclasses that need to be owned
   // by this object. Is created on first call to |GetDBUserData()|.
   scoped_ptr<SupportsUserDataAggregatable> user_data_;
 
   WebDatabase::State RemoveExpiredFormElementsImpl(WebDatabase* db);
 
   // 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_;
 
   // WebDataServiceBackend allows direct access to DB.
   // TODO(caitkp): Make it so nobody but us needs direct DB access anymore.
   scoped_refptr<WebDataServiceBackend> web_database_backend_;
 
   base::Closure on_changed_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(AutofillWebDataBackendImpl);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOFILL_WEBDATA_BACKEND_IMPL_H_