Update the request count when a request fails.

components/offline_pages/background/request_queue.h

 // Copyright 2016 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_OFFLINE_PAGES_BACKGROUND_REQUEST_QUEUE_H_
 #define COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_QUEUE_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 
 namespace offline_pages {
 
 class RequestQueueStore;
 class SavePageRequest;
 
 // Class responsible for managing save page requests.
 class RequestQueue {
  public:
   enum class GetRequestsResult {
@@ skipping 43 matching lines @@
 
   // Updates a request in the request queue if a request with matching ID
   // exists. Does nothing otherwise. Result is returned through |callback|.
   void UpdateRequest(const SavePageRequest& request,
                      const UpdateRequestCallback& callback);
 
   // Removes the request matching the |request_id|. Result is returned through
   // |callback|.
   void RemoveRequest(int64_t request_id, const UpdateRequestCallback& callback);
 
+  void GetForUpdateDone(
+      const RequestQueue::UpdateRequestCallback& update_callback,
+      const SavePageRequest& update_request,
+      bool success,
+      const std::vector<SavePageRequest>& requests);
+
  private:
   // Callback used by |PurgeRequests|.
   typedef base::Callback<void(UpdateRequestResult,
                               int /* removed requests count */)>
       PurgeRequestsCallback;
 
   // Purges the queue, removing the requests that are no longer relevant, e.g.
   // expired request. Result is returned through |callback| carries the number
   // of removed requests.
   void PurgeRequests(const PurgeRequestsCallback& callback);
 
   std::unique_ptr<RequestQueueStore> store_;
 
+  // Allows us to pass a weak pointer to callbacks.
+  base::WeakPtrFactory<RequestQueue> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(RequestQueue);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_QUEUE_H_