[Offline pages] Updating RequestQueue::RemoveRequests to use a TaskQueue

components/offline_pages/background/request_queue.cc

Index: components/offline_pages/background/request_queue.cc
diff --git a/components/offline_pages/background/request_queue.cc b/components/offline_pages/background/request_queue.cc
index 0b562066d8d20159ed7c1a2bd9ce447527bf18ff..b491824edebd3870ab479ec1973d939f3bb0115e 100644
--- a/components/offline_pages/background/request_queue.cc
+++ b/components/offline_pages/background/request_queue.cc
@@ -8,6 +8,7 @@
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/offline_pages/background/change_requests_state_task.h"
+#include "components/offline_pages/background/remove_requests_task.h"
 #include "components/offline_pages/background/request_queue_store.h"
 #include "components/offline_pages/background/save_page_request.h"
 
@@ -73,14 +74,6 @@ void UpdateRequestsDone(const RequestQueue::UpdateRequestCallback& callback,
   callback.Run(result);
 }
 
-// Completes the remove request call.
-void RemoveRequestsDone(
-    const RequestQueue::RemoveRequestsCallback& callback,
-    const RequestQueue::UpdateMultipleRequestResults& results,
-    std::vector<std::unique_ptr<SavePageRequest>> requests) {
-  callback.Run(results, std::move(requests));
-}
-
 }  // namespace
 
 RequestQueue::RequestQueue(std::unique_ptr<RequestQueueStore> store)
@@ -151,8 +144,10 @@ void RequestQueue::GetForUpdateDone(
 }
 
 void RequestQueue::RemoveRequests(const std::vector<int64_t>& request_ids,
-                                  const RemoveRequestsCallback& callback) {
-  store_->RemoveRequests(request_ids, base::Bind(RemoveRequestsDone, callback));
+                                  const UpdateCallback& callback) {
+  std::unique_ptr<Task> task(
+      new RemoveRequestsTask(store_.get(), request_ids, callback));
+  task_queue_.AddTask(std::move(task));
 }
 
 void RequestQueue::ChangeRequestsState(