[Offline Pages] Duplicate pages when save/delete bookmarks.

components/offline_pages/offline_page_model.h

Index: components/offline_pages/offline_page_model.h
diff --git a/components/offline_pages/offline_page_model.h b/components/offline_pages/offline_page_model.h
index 9d73acef9ceecb20214891b5eca1097aebd9540c..a12c38aa698358431c3f0f9bc7d07f091c4dfba5 100644
--- a/components/offline_pages/offline_page_model.h
+++ b/components/offline_pages/offline_page_model.h
@@ -74,6 +74,9 @@ class OfflinePageModel : public base::SupportsUserData {
   // Returns true if saving an offline page may be attempted for |url|.
   static bool CanSaveURL(const GURL& url);
 
+  // Returns true if the page with |client_id| is initiated by user.
+  static bool IsUserInitiated(const ClientId& client_id);
+
   OfflinePageModel();
   ~OfflinePageModel() override;