mus: Add debug key to print the server window hierarchy

components/mus/ws/server_window.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_MUS_WS_SERVER_WINDOW_H_
 #define COMPONENTS_MUS_WS_SERVER_WINDOW_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 115 matching lines @@
   void SetPredefinedCursor(mus::mojom::Cursor cursor_id);
 
   const gfx::Transform& transform() const { return transform_; }
   void SetTransform(const gfx::Transform& transform);
 
   const std::map<std::string, std::vector<uint8_t>>& properties() const {
     return properties_;
   }
   void SetProperty(const std::string& name, const std::vector<uint8_t>* value);
 
+  std::string GetName() const;
+
   void SetTextInputState(const ui::TextInputState& state);
   const ui::TextInputState& text_input_state() const {
     return text_input_state_;
   }
 
   void set_can_focus(bool can_focus) { can_focus_ = can_focus; }
   bool can_focus() const { return can_focus_; }
 
   // Returns true if this window is attached to a root and all ancestors are
   // visible.
@@ skipping 77 matching lines @@
 
   base::ObserverList<ServerWindowObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(ServerWindow);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_SERVER_WINDOW_H_