Remove DeleteTask and convert remaining users.

chrome/browser/webdata/web_data_service.h

 // Copyright (c) 2011 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_WEB_DATA_SERVICE_H__
 #define CHROME_BROWSER_WEBDATA_WEB_DATA_SERVICE_H__
 #pragma once
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/file_path.h"
 #include "base/location.h"
+#include "base/message_loop_helpers.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/search_engines/template_url_id.h"
 #include "content/public/browser/browser_thread.h"
 #include "sql/init_status.h"
 
 class AutocompleteSyncableService;
 class AutofillChange;
 class AutofillProfile;
 class AutofillProfileSyncableService;
@@ skipping 538 matching lines @@
   void RegisterRequest(WebDataRequest* request);
 
   //////////////////////////////////////////////////////////////////////////////
   //
   // The following methods are only invoked in the web data service thread.
   //
   //////////////////////////////////////////////////////////////////////////////
  private:
   friend struct content::BrowserThread::DeleteOnThread<
       content::BrowserThread::UI>;
-  friend class DeleteTask<WebDataService>;
-  friend class ShutdownTask;
+  friend class base::DeleteHelper<WebDataService>;
 
   typedef GenericRequest2<std::vector<const TemplateURL*>,
                           std::vector<TemplateURL*> > SetKeywordsRequest;
 
   // Invoked on the main thread if initializing the db fails.
   void DBInitFailed(sql::InitStatus init_status);
 
   // Initialize the database, if it hasn't already been initialized.
   void InitializeDatabaseIfNecessary();
 
@@ skipping 168 matching lines @@
   // result can be NULL, if no result is expected or if the database could
   // not be opened. The result object is destroyed after this call.
   virtual void OnWebDataServiceRequestDone(WebDataService::Handle h,
                                            const WDTypedResult* result) = 0;
 
  protected:
   virtual ~WebDataServiceConsumer() {}
 };
 
 #endif  // CHROME_BROWSER_WEBDATA_WEB_DATA_SERVICE_H__