views/mus: Recreate WindowManagerConnection for each test.

ui/views/mus/window_manager_connection.cc

 // Copyright 2015 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/views/mus/window_manager_connection.h"
 
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/threading/thread_local.h"
@@ skipping 111 matching lines @@
       base::Unretained(this),
       std::map<std::string, std::vector<uint8_t>>()));
 }
 
 WindowManagerConnection::~WindowManagerConnection() {
   // ~WindowTreeClient calls back to us (we're its delegate), destroy it while
   // we are still valid.
   client_.reset();
   if (created_device_data_manager_)
     ui::DeviceDataManager::DeleteInstance();
+
+  if (ViewsDelegate::GetInstance()) {
+    ViewsDelegate::GetInstance()->set_native_widget_factory(
+        ViewsDelegate::NativeWidgetFactory());
+  }
 }
 
 bool WindowManagerConnection::HasPointerWatcher() {
   // Check to see if we really have any observers left. This doesn't use
   // base::ObserverList<>::might_have_observers() because that returns true
   // during iteration over the list even when the last observer is removed.
   base::ObserverList<PointerWatcher>::Iterator iterator(&pointer_watchers_);
   return !!iterator.GetNext();
 }
 
@@ skipping 30 matching lines @@
 void WindowManagerConnection::OnWindowManagerFrameValuesChanged() {
   if (client_)
     NativeWidgetMus::NotifyFrameChanged(client_.get());
 }
 
 gfx::Point WindowManagerConnection::GetCursorScreenPoint() {
   return client_->GetCursorScreenPoint();
 }
 
 }  // namespace views