Remove SurfaceSequence from mus client code.

services/ui/public/cpp/surface_id_handler.h

 // Copyright 2016 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_SURFACE_ID_HANDLER_H_
 #define SERVICES_UI_PUBLIC_CPP_SURFACE_ID_HANDLER_H_
 
 #include "cc/surfaces/surface_id.h"
-#include "cc/surfaces/surface_sequence.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace ui {
 
 class Window;
 
 // Holds information about the current surface held by a Window.
 // |surface_id| uniquely identifies the surface in the display
 // compositor.
-// |surface_sequence| is a reference to the surface to retain
-// this surface even after a new surface has been created.
 // |frame_size| is the size of the frame held by the surface.
 // |device_scale_factor| is the scale factor that the frame was
 // renderered for.
 struct SurfaceInfo {
   cc::SurfaceId surface_id;
-  cc::SurfaceSequence surface_sequence;
   gfx::Size frame_size;
   float device_scale_factor;
 };
 
 class SurfaceIdHandler {
  public:
   // Called when a child window allocates a new surface ID.
   // If the handler wishes to retain ownership of the |surface_info|,
   // it can move it. If a child's surface has been cleared then
   // |surface_info| will refer to a null pointer.
   virtual void OnChildWindowSurfaceChanged(
       Window* window,
       std::unique_ptr<SurfaceInfo>* surface_info) = 0;
 };
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_PUBLIC_CPP_SURFACE_ID_HANDLER_H_