Cancel prerendering when a request is paused or removed.

components/offline_pages/background/request_coordinator.h

Index: components/offline_pages/background/request_coordinator.h
diff --git a/components/offline_pages/background/request_coordinator.h b/components/offline_pages/background/request_coordinator.h
index 2b874332bc58508c60d21a306186a16b792aed2c..8f203d8c496bd6b24f77008b5e203c918e9e9b88 100644
--- a/components/offline_pages/background/request_coordinator.h
+++ b/components/offline_pages/background/request_coordinator.h
@@ -174,6 +174,9 @@ class RequestCoordinator : public KeyedService, public RequestNotifier {
   // Callback from the request picker when no more requests are in the queue.
   void RequestQueueEmpty();
 
+  // Cancels an in progress pre-rendering, and updates state appropriately.
+  void StopPrerendering();
+
   void SendRequestToOffliner(const SavePageRequest& request);
 
   // Called by the offliner when an offlining request is completed. (and by
@@ -183,6 +186,9 @@ class RequestCoordinator : public KeyedService, public RequestNotifier {
 
   void TryNextRequest();
 
+  // If there is an active request in the list, cancel that request.
+  bool CancelActiveRequestIfItMatches(const std::vector<int64_t>& request_ids);
+
   // Returns the appropriate offliner to use, getting a new one from the factory
   // if needed.
   void GetOffliner();