Add an API to Pause and Resume background offlining requests.

components/offline_pages/background/request_queue.cc

 // 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.
 
 #include "components/offline_pages/background/request_queue.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/offline_pages/background/request_queue_store.h"
@@ skipping 112 matching lines @@
   // Since the request exists, update it.
   store_->AddOrUpdateRequest(update_request,
                              base::Bind(&UpdateRequestDone, update_callback));
 }
 
 void RequestQueue::RemoveRequests(const std::vector<int64_t>& request_ids,
                                   const RemoveRequestsCallback& callback) {
   store_->RemoveRequests(request_ids, base::Bind(RemoveRequestsDone, callback));
 }
 
+void RequestQueue::ChangeRequestsState(
+    const std::vector<int64_t>& request_ids,
+    const SavePageRequest::RequestState new_state,
+    const UpdateRequestCallback& callback) {
+  store_->ChangeRequestsState(request_ids, new_state,
+                              base::Bind(UpdateRequestDone, callback));
+}
+
 void RequestQueue::PurgeRequests(const PurgeRequestsCallback& callback) {}
 
 }  // namespace offline_pages