a CompositeUndoStackObserver is still an UndoStackObserver -- forgot about that

diff --git a/src/composite-undo-stack-observer.h b/src/composite-undo-stack-observer.h
index 908610135a11c829a61841653cf6c21fa12983c8..fbe0ed892cf20cbb041cf67da9a48e12dea036d0 100644 (file)
--- a/src/composite-undo-stack-observer.h
+++ b/src/composite-undo-stack-observer.h
@@ -26,13 +26,11 @@ class Event;
 
 }
 
-class UndoStackObserver;
-
 /**
  * Aggregates UndoStackObservers for management and triggering in an SPDocument's undo/redo
  * system.
  */
-class CompositeUndoStackObserver {
+class CompositeUndoStackObserver : public UndoStackObserver {
 public:
 
        /**