Try to get rid of all direct references to particular native themes.

ui/views/mus/native_widget_mus.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.
 
 // This has to be before any other includes, else default is picked up.
 // See base/logging for details on this.
 #define NOTIMPLEMENTED_POLICY 5
 
 #include "ui/views/mus/native_widget_mus.h"
 
@@ skipping 20 matching lines @@
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/mus/mus_util.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_property.h"
 #include "ui/base/hit_test.h"
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
 #include "ui/events/event.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/path.h"
-#include "ui/native_theme/native_theme_aura.h"
+#include "ui/native_theme/native_theme.h"
 #include "ui/platform_window/platform_window_delegate.h"
 #include "ui/views/corewm/tooltip.h"
 #include "ui/views/corewm/tooltip_aura.h"
 #include "ui/views/corewm/tooltip_controller.h"
 #include "ui/views/drag_utils.h"
 #include "ui/views/mus/drag_drop_client_mus.h"
 #include "ui/views/mus/drop_target_mus.h"
 #include "ui/views/mus/input_method_mus.h"
 #include "ui/views/mus/window_manager_connection.h"
 #include "ui/views/mus/window_manager_constants_converters.h"
@@ skipping 1256 matching lines @@
     const base::TimeDelta& duration) {
   NOTIMPLEMENTED();
 }
 
 void NativeWidgetMus::SetVisibilityAnimationTransition(
     Widget::VisibilityTransition transition) {
   NOTIMPLEMENTED();
 }
 
 ui::NativeTheme* NativeWidgetMus::GetNativeTheme() const {
-  return ui::NativeThemeAura::instance();
+  return ui::NativeTheme::GetInstanceForNativeUi();
 }
 
 void NativeWidgetMus::OnRootViewLayout() {
   NOTIMPLEMENTED();
 }
 
 bool NativeWidgetMus::IsTranslucentWindowOpacitySupported() const {
   NOTIMPLEMENTED();
   return true;
 }
@@ skipping 240 matching lines @@
 
   gfx::Path mask_path;
   native_widget_delegate_->GetHitTestMask(&mask_path);
   // TODO(jamescook): Use the full path for the mask.
   gfx::Rect mask_rect =
       gfx::ToEnclosingRect(gfx::SkRectToRectF(mask_path.getBounds()));
   window_->SetHitTestMask(mask_rect);
 }
 
 }  // namespace views