Add an API to Pause and Resume background offlining requests.

components/offline_pages/background/request_coordinator.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_COORDINATOR_H_
 #define COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_
 
 #include <memory>
 
 #include "base/callback.h"
@@ skipping 37 matching lines @@
   // Queues |request| to later load and save when system conditions allow.
   // Returns true if the page could be queued successfully.
   bool SavePageLater(
       const GURL& url, const ClientId& client_id, bool user_reqeusted);
 
   // Remove a list of requests by |request_id|.  This removes requests from the
   // request queue, but does not cancel an in-progress pre-render.
   // TODO(petewil): Add code to cancel an in-progress pre-render.
   void RemoveRequests(const std::vector<int64_t>& request_ids);
 
-  // Callback that receives the response for GetRequests.  Client must
+  // Pause a list of requests by |request_id|.  This will change the state
+  // in the request queue so the request cannot be started.
+  // TODO(petewil): Add code to cancel an in-progress pre-render.
+  void PauseRequests(const std::vector<int64_t>& request_ids);
+
+  // Resume a list of previously paused requests, making them available.
+  void ResumeRequests(const std::vector<int64_t>& request_ids);
+
+  // Callback that receives the response for GetAllRequests.  Client must
   // copy the result right away, it goes out of scope at the end of the
   // callback.
   typedef base::Callback<void(const std::vector<SavePageRequest>&)>
       GetRequestsCallback;
 
   // Get all save page request items in the callback.
   void GetAllRequests(const GetRequestsCallback& callback);
 
   // Starts processing of one or more queued save page later requests.
   // Returns whether processing was started and that caller should expect
@@ skipping 123 matching lines @@
   base::TimeDelta offliner_timeout_;
   // Allows us to pass a weak pointer to callbacks.
   base::WeakPtrFactory<RequestCoordinator> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RequestCoordinator);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_