services/ui: Fix new GPU code path on Windows.

services/ui/gpu/gpu_service_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 "services/ui/gpu/gpu_service_mus.h"
 
 #include "base/memory/shared_memory.h"
 #include "base/memory/singleton.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 128 matching lines @@
 void GpuServiceMus::StoreShaderToDisk(int client_id,
                                       const std::string& key,
                                       const std::string& shader) {
   NOTIMPLEMENTED();
 }
 
 #if defined(OS_WIN)
 void GpuServiceMus::SendAcceleratedSurfaceCreatedChildWindow(
     gpu::SurfaceHandle parent_window,
     gpu::SurfaceHandle child_window) {
-  NOTIMPLEMENTED();
+  ::SetParent(child_window, parent_window);
 }
 #endif
 
 void GpuServiceMus::SetActiveURL(const GURL& url) {
   // TODO(penghuang): implement this function.
 }
 
 void GpuServiceMus::Initialize() {
   DCHECK(CalledOnValidThread());
   base::Thread::Options thread_options(base::MessageLoop::TYPE_DEFAULT, 0);
@@ skipping 104 matching lines @@
   return shm;
 }
 
 // static
 GpuServiceMus* GpuServiceMus::GetInstance() {
   return base::Singleton<GpuServiceMus,
                          base::LeakySingletonTraits<GpuServiceMus>>::get();
 }
 
 }  // namespace ui