mus: Make sure window parenting happens in the window server.

services/ui/gpu/gpu_service.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 "services/ui/gpu/gpu_service.h"
 
 #include "base/bind.h"
 #include "base/memory/shared_memory.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
@@ skipping 126 matching lines @@
 void GpuService::StoreShaderToDisk(int client_id,
                                    const std::string& key,
                                    const std::string& shader) {
   gpu_host_->StoreShaderToDisk(client_id, key, shader);
 }
 
 #if defined(OS_WIN)
 void GpuService::SendAcceleratedSurfaceCreatedChildWindow(
     gpu::SurfaceHandle parent_window,
     gpu::SurfaceHandle child_window) {
-  ::SetParent(child_window, parent_window);
+  gpu_host_->SetChildSurface(parent_window, child_window);
 }
 #endif
 
 void GpuService::SetActiveURL(const GURL& url) {
   // TODO(penghuang): implement this function.
 }
 
 void GpuService::EstablishGpuChannel(
     int32_t client_id,
     uint64_t client_tracing_id,
@@ skipping 12 matching lines @@
   mojo::ScopedMessagePipeHandle channel_handle;
   IPC::ChannelHandle handle = gpu_channel_manager_->EstablishChannel(
       client_id, client_tracing_id, preempts, allow_view_command_buffers,
       allow_real_time_streams);
   channel_handle.reset(handle.mojo_handle);
   media_gpu_channel_manager_->AddChannel(client_id);
   callback.Run(std::move(channel_handle));
 }
 
 }  // namespace ui