aura: Make 'ui' buildable without gtk.

ui/gfx/insets.h

 // Copyright (c) 2011 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_GFX_INSETS_H_
 #define UI_GFX_INSETS_H_
 #pragma once
 
 #include <string>
 
 #include "build/build_config.h"
 #include "ui/base/ui_export.h"
 
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
+#if defined(TOOLKIT_USES_GTK)
 #include <gtk/gtkstyle.h>
 #endif
 
 namespace gfx {
 
 //
 // An insets represents the borders of a container (the space the container must
 // leave at each of its edges).
 //
 
 class UI_EXPORT Insets {
  public:
   Insets() : top_(0), left_(0), bottom_(0), right_(0) {}
   Insets(int top, int left, int bottom, int right)
       : top_(top),
         left_(left),
         bottom_(bottom),
         right_(right) {}
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
+#if defined(TOOLKIT_USES_GTK)
   explicit Insets(const GtkBorder& border)
       : top_(border.top),
         left_(border.left),
         bottom_(border.bottom),
         right_(border.right) {}
 #endif
 
   ~Insets() {}
 
   int top() const { return top_; }
@@ skipping 42 matching lines @@
  private:
   int top_;
   int left_;
   int bottom_;
   int right_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_INSETS_H_