Getting rid of SurfaceIdHandler as it is no longer needed.

ui/aura/mus/window_port_mus.cc

 // 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.
 
 #include "ui/aura/mus/window_port_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/transient_window_client.h"
 #include "ui/aura/mus/client_surface_embedder.h"
 #include "ui/aura/mus/property_converter.h"
-#include "ui/aura/mus/surface_id_handler.h"
 #include "ui/aura/mus/window_tree_client.h"
 #include "ui/aura/mus/window_tree_client_delegate.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_observer.h"
 #include "ui/aura/window_property.h"
 
 namespace aura {
 
 WindowPortMus::WindowMusChangeDataImpl::WindowMusChangeDataImpl() = default;
@@ skipping 225 matching lines @@
 void WindowPortMus::SetSurfaceInfoFromServer(
     const cc::SurfaceInfo& surface_info) {
   if (surface_info_.id().is_valid()) {
     const cc::SurfaceId& existing_surface_id = surface_info_.id();
     const cc::SurfaceId& new_surface_id = surface_info.id();
     if (existing_surface_id.is_valid() &&
         existing_surface_id != new_surface_id) {
       // TODO(kylechar): Start return reference here?
     }
   }
-  WindowPortMus* parent = Get(window_->parent());
-  // TODO(mfomitchev): This is unused. We probably don't need this.
-  if (parent && parent->surface_id_handler_) {
-    parent->surface_id_handler_->OnChildWindowSurfaceChanged(window_,
-                                                             surface_info);
-  }
 
   // The fact that SetSurfaceIdFromServer was called means that this window
   // corresponds to an embedded client.
   if (!client_surface_embedder && surface_info.id().is_valid())
     client_surface_embedder = base::MakeUnique<ClientSurfaceEmbedder>(window_);
 
   if (surface_info.id().is_valid())
     client_surface_embedder->UpdateSurface(surface_info);
   else
     client_surface_embedder.reset();
@@ skipping 164 matching lines @@
   change_data.property_name =
       GetPropertyConverter()->GetTransportNameForPropertyKey(key);
   // TODO(sky): investigate to see if we need to compare data. In particular do
   // we ever have a case where changing a property cascades into changing the
   // same property?
   if (!RemoveChangeByTypeAndData(ServerChangeType::PROPERTY, change_data))
     window_tree_client_->OnWindowMusPropertyChanged(this, key, std::move(data));
 }
 
 }  // namespace aura