Getting rid of SurfaceIdHandler as it is no longer needed.

ui/aura/mus/window_tree_client.cc

 // 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.
 
 #include "ui/aura/mus/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 11 matching lines @@
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/client/transient_window_client.h"
 #include "ui/aura/mus/capture_synchronizer.h"
 #include "ui/aura/mus/drag_drop_controller_mus.h"
 #include "ui/aura/mus/focus_synchronizer.h"
 #include "ui/aura/mus/in_flight_change.h"
 #include "ui/aura/mus/input_method_mus.h"
 #include "ui/aura/mus/property_converter.h"
 #include "ui/aura/mus/property_utils.h"
-#include "ui/aura/mus/surface_id_handler.h"
 #include "ui/aura/mus/window_manager_delegate.h"
 #include "ui/aura/mus/window_mus.h"
 #include "ui/aura/mus/window_port_mus.h"
 #include "ui/aura/mus/window_tree_client_delegate.h"
 #include "ui/aura/mus/window_tree_client_observer.h"
 #include "ui/aura/mus/window_tree_host_mus.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_tracker.h"
 #include "ui/base/ui_base_types.h"
@@ skipping 1649 matching lines @@
   return ScheduleInFlightChange(base::MakeUnique<InFlightCaptureChange>(
       this, capture_synchronizer_.get(), window));
 }
 
 uint32_t WindowTreeClient::CreateChangeIdForFocus(WindowMus* window) {
   return ScheduleInFlightChange(base::MakeUnique<InFlightFocusChange>(
       this, focus_synchronizer_.get(), window));
 }
 
 }  // namespace aura