Delete the GTK+ port of Chrome.

ui/native_theme/native_theme_gtk.h

Index: ui/native_theme/native_theme_gtk.h
diff --git a/ui/native_theme/native_theme_gtk.h b/ui/native_theme/native_theme_gtk.h
deleted file mode 100644
index 05f5a8cd7b493350ae994077d1ed6b9fb3559bbb..0000000000000000000000000000000000000000
--- a/ui/native_theme/native_theme_gtk.h
+++ /dev/null
@@ -1,28 +0,0 @@
-// 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.
-
-#ifndef UI_NATIVE_THEME_NATIVE_THEME_GTK_H_
-#define UI_NATIVE_THEME_NATIVE_THEME_GTK_H_
-
-#include "ui/native_theme/native_theme_base.h"
-
-namespace ui {
-
-// GTK implementation of native theme support.
-class NativeThemeGtk : public NativeThemeBase {
- public:
-  static NativeThemeGtk* instance();
-
-  virtual SkColor GetSystemColor(ColorId color_id) const OVERRIDE;
-
- private:
-  NativeThemeGtk();
-  virtual ~NativeThemeGtk();
-
-  DISALLOW_COPY_AND_ASSIGN(NativeThemeGtk);
-};
-
-}  // namespace ui
-
-#endif  // UI_NATIVE_THEME_NATIVE_THEME_GTK_H_