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ui/aura/window_observer.h

Index: ui/aura/window_observer.h
diff --git a/ui/aura/window_observer.h b/ui/aura/window_observer.h
index fd71a5f62a2d47fff88ed4b2ecb186e5fe5032ff..224f0d0474627f659fa6e42fb2ae671ae8d359ce 100644
--- a/ui/aura/window_observer.h
+++ b/ui/aura/window_observer.h
@@ -20,6 +20,11 @@ class AURA_EXPORT WindowObserver {
   // Invoked prior to removing |window|.
   virtual void OnWillRemoveWindow(Window* window) {}
 
+  // Invoked when the SetVisible() is invoked on a window. |visible| is the
+  // value supplied to SetVisible(). If |visible| is true, window->IsVisible()
+  // may still return false. See description in Window::IsVisible() for details.
+  virtual void OnWindowVisibilityChanged(Window* window, bool visibile) {}
+
  protected:
   virtual ~WindowObserver() {}
 };