Add an API to Pause and Resume background offlining requests.

components/offline_pages/background/request_queue.h

Index: components/offline_pages/background/request_queue.h
diff --git a/components/offline_pages/background/request_queue.h b/components/offline_pages/background/request_queue.h
index 429c3757b89acc1cec1d65eb7cab9bc9fc604378..e294a6859ad3f27dae6a1f6e85746125ebad6531 100644
--- a/components/offline_pages/background/request_queue.h
+++ b/components/offline_pages/background/request_queue.h
@@ -83,6 +83,16 @@ class RequestQueue {
   void RemoveRequestsByClientId(const std::vector<ClientId>& client_id,
                                 const UpdateRequestCallback& callback);
 
+  // Pauses the requests matching the |request_ids|. Results are returned
+  // through |callback|.
+  void PauseRequests(const std::vector<int64_t>& request_ids,
+                               const UpdateRequestCallback& callback);
+
+  // Resumes the requests matching the |request_ids|. Results are returned
+  // through |callback|.
+  void ResumeRequests(const std::vector<int64_t>& request_ids,
+                                const UpdateRequestCallback& callback);
+
   void GetForUpdateDone(
       const RequestQueue::UpdateRequestCallback& update_callback,
       const SavePageRequest& update_request,