Provide API in RequestCoordinator to remove results by client ID.

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 869f072e1f69594fa99e2999fe624176568d180c..4c19550d01b27ad7481846121e01157e22195512 100644
--- a/components/offline_pages/background/request_queue.h
+++ b/components/offline_pages/background/request_queue.h
@@ -13,6 +13,7 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "components/offline_pages/offline_page_item.h"
 
 namespace offline_pages {
 
@@ -76,6 +77,11 @@ class RequestQueue {
   // |callback|.
   void RemoveRequest(int64_t request_id, const UpdateRequestCallback& callback);
 
+  // Removes the requests matching the |client_ids|. Results are returned
+  // through |callback|.
+  void RemoveRequestsByClientId(const std::vector<ClientId>& client_id,
+                                const UpdateRequestCallback& callback);
+
   void GetForUpdateDone(
       const RequestQueue::UpdateRequestCallback& update_callback,
       const SavePageRequest& update_request,