Remove DeleteTask and convert remaining users.

chrome/browser/search_engines/search_provider_install_data.cc

 // 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.
 
 #include "chrome/browser/search_engines/search_provider_install_data.h"
 
 #include <algorithm>
 #include <functional>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
+#include "base/message_loop_helpers.h"
 #include "chrome/browser/search_engines/search_host_to_urls_map.h"
 #include "chrome/browser/search_engines/search_terms_data.h"
 #include "chrome/browser/search_engines/template_url.h"
 #include "chrome/browser/search_engines/template_url_service.h"
 #include "chrome/browser/search_engines/util.h"
 #include "chrome/browser/webdata/web_data_service.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
@@ skipping 49 matching lines @@
  public:
   explicit GoogleURLChangeNotifier(
       const base::WeakPtr<SearchProviderInstallData>& install_data);
 
   // Called on the I/O thread with the Google base URL whenever the value
   // changes.
   void OnChange(const std::string& google_base_url);
 
  private:
   friend struct BrowserThread::DeleteOnThread<BrowserThread::IO>;
-  friend class DeleteTask<GoogleURLChangeNotifier>;
+  friend class base::DeleteHelper<GoogleURLChangeNotifier>;
 
   ~GoogleURLChangeNotifier() {}
 
   base::WeakPtr<SearchProviderInstallData> install_data_;
 
   DISALLOW_COPY_AND_ASSIGN(GoogleURLChangeNotifier);
 };
 
 GoogleURLChangeNotifier::GoogleURLChangeNotifier(
     const base::WeakPtr<SearchProviderInstallData>& install_data)
@@ skipping 211 matching lines @@
 
   std::for_each(closure_queue.begin(),
                 closure_queue.end(),
                 std::mem_fun_ref(&base::Closure::Run));
 
   // Since we expect this request to be rare, clear out the information. This
   // also keeps the responses current as the search providers change.
   provider_map_.reset();
   SetDefault(NULL);
 }