mus: Add debug key to print the server window hierarchy

components/mus/ws/window_manager_state.h

Index: components/mus/ws/window_manager_state.h
diff --git a/components/mus/ws/window_manager_state.h b/components/mus/ws/window_manager_state.h
index 8f967343c5eb9a9fc8653e68d87e1ddee974508f..ad0628f817cd69e84c8a1d6db4a2fbc0319f49af 100644
--- a/components/mus/ws/window_manager_state.h
+++ b/components/mus/ws/window_manager_state.h
@@ -153,6 +153,9 @@ class WindowManagerState : public EventDispatcherDelegate {
                                       const ui::Event& event,
                                       base::WeakPtr<Accelerator> accelerator);
 
+  // Handles debugging shortcuts in debug builds. The events are not consumed.
+  void RunDebugShortcuts(const ui::Event& event);
+
   // EventDispatcherDelegate:
   void OnAccelerator(uint32_t accelerator_id, const ui::Event& event) override;
   void SetFocusedWindowFromEventDispatcher(ServerWindow* window) override;