views/mus: Fix some flaky crashes during test teardown.

ui/views/widget/widget_unittest.cc

 // Copyright (c) 2012 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 <algorithm>
 #include <memory>
 #include <set>
 
 #include "base/bind.h"
 #include "base/macros.h"
@@ skipping 1934 matching lines @@
   generator.ClickLeftButton();
   EXPECT_FALSE(deletion_observer.IsWidgetAlive());
 
   // Yay we did not crash!
 }
 
 // No touch on desktop Mac. Tracked in http://crbug.com/445520.
 #if !defined(OS_MACOSX) || defined(USE_AURA)
 
 TEST_F(WidgetTest, WidgetDeleted_InDispatchGestureEvent) {
-  // This test doesn't make sense for mus. Force NativeWidgetAura to be used.
-  DisableNativeWidgetMus();
+  // This test doesn't make sense for mus.
+  if (IsMus())
+    return;
 
   Widget* widget = new Widget;
   Widget::InitParams params =
       CreateParams(views::Widget::InitParams::TYPE_POPUP);
   widget->Init(params);
 
   widget->SetContentsView(new CloseWidgetView(ui::ET_GESTURE_TAP_DOWN));
 
   widget->SetSize(gfx::Size(100, 100));
   widget->Show();
@@ skipping 1743 matching lines @@
   EXPECT_FALSE(!!IsWindow(owned_hwnd));
   EXPECT_TRUE(!!IsWindowEnabled(top_hwnd));
 
   top_level_widget.CloseNow();
 }
 
 #endif  // defined(OS_WIN)
 
 }  // namespace test
 }  // namespace views