WIP: Propagate SurfaceID up window tree hierarchy

services/ui/public/cpp/window_observer.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 SERVICES_UI_PUBLIC_CPP_WINDOW_OBSERVER_H_
 #define SERVICES_UI_PUBLIC_CPP_WINDOW_OBSERVER_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 30 matching lines @@
   virtual void OnWindowReordering(Window* window,
                                   Window* relative_window,
                                   mojom::OrderDirection direction) {}
   virtual void OnWindowReordered(Window* window,
                                  Window* relative_window,
                                  mojom::OrderDirection direction) {}
 
   virtual void OnWindowDestroying(Window* window) {}
   virtual void OnWindowDestroyed(Window* window) {}
 
+  virtual void OnChildWindowSurfaceCreated(
+      Window* window,
+      const gfx::Size& size,
+      float device_scale_factor,
+      const cc::SurfaceId& surface_id,
+      const cc::SurfaceSequence& surface_sequence) {}
+
   virtual void OnWindowBoundsChanging(Window* window,
                                       const gfx::Rect& old_bounds,
                                       const gfx::Rect& new_bounds) {}
   virtual void OnWindowBoundsChanged(Window* window,
                                      const gfx::Rect& old_bounds,
                                      const gfx::Rect& new_bounds) {}
   virtual void OnWindowLostCapture(Window* window) {}
   virtual void OnWindowClientAreaChanged(
       Window* window,
       const gfx::Insets& old_client_area,
@@ skipping 45 matching lines @@
   // allows the close it should destroy the window as appropriate.
   virtual void OnRequestClose(Window* window) {}
 
  protected:
   virtual ~WindowObserver() {}
 };
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_PUBLIC_CPP_WINDOW_OBSERVER_H_