Provide API in RequestCoordinator to remove results by client ID.

components/offline_pages/background/request_coordinator.cc

Index: components/offline_pages/background/request_coordinator.cc
diff --git a/components/offline_pages/background/request_coordinator.cc b/components/offline_pages/background/request_coordinator.cc
index 5876d8386d79b7c3834f6cf9b7d72bd22f8c38cd..65554607d702d9b9a04563ecff50a5cda840330d 100644
--- a/components/offline_pages/background/request_coordinator.cc
+++ b/components/offline_pages/background/request_coordinator.cc
@@ -70,6 +70,13 @@ bool RequestCoordinator::SavePageLater(
   return true;
 }
 
+void RequestCoordinator::RemoveRequests(
+    const std::vector<ClientId>& client_ids) {
+  queue_->RemoveRequestsByClientId(
+      client_ids, base::Bind(&RequestCoordinator::UpdateRequestCallback,
+                             weak_ptr_factory_.GetWeakPtr()));
+}
+
 void RequestCoordinator::AddRequestResultCallback(
     RequestQueue::AddRequestResult result,
     const SavePageRequest& request) {