Reduce frequency of requesting bookmark clusters.

components/enhanced_bookmarks/enhanced_bookmark_model_observer.h

Index: components/enhanced_bookmarks/enhanced_bookmark_model_observer.h
diff --git a/components/enhanced_bookmarks/enhanced_bookmark_model_observer.h b/components/enhanced_bookmarks/enhanced_bookmark_model_observer.h
index 5ebfa16e41795c1e2cf0ece7fbaa69c5e1332b2d..eb83b57e762f36c65b1f0790bebf2e9858912671 100644
--- a/components/enhanced_bookmarks/enhanced_bookmark_model_observer.h
+++ b/components/enhanced_bookmarks/enhanced_bookmark_model_observer.h
@@ -25,6 +25,9 @@ class EnhancedBookmarkModelObserver {
   // Called when a node is removed from the model.
   virtual void EnhancedBookmarkRemoved(const BookmarkNode* node) = 0;
 
+  // Called when a node has changed.
+  virtual void EnhancedBookmarkNodeChanged(const BookmarkNode* node) = 0;
+
   // Called when all user editable nodes are removed from the model.
   virtual void EnhancedBookmarkAllUserNodesRemoved() = 0;