Introduce ui.dll / libui.so for the component build.

ui/gfx/native_theme.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_NATIVE_THEME_H_
 #define UI_GFX_NATIVE_THEME_H_
 #pragma once
 
 #include "skia/ext/platform_canvas.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/ui_api.h"
 
 namespace gfx {
 
 class Rect;
 class Size;
 
 // This class supports drawing UI controls (like buttons, text fields, lists,
 // comboboxes, etc) that look like the native UI controls of the underlying
 // platform, such as Windows or Linux.
 //
 // The supported control types are listed in the Part enum.  These parts can be
 // in any state given by the State enum, where the actual definititon of the
 // state is part-specific.
 //
 // Some parts require more information than simply the state in order to be
 // drawn correctly, and this information is given to the Paint() method via the
 // ExtraParams union.  Each part that requires more information has its own
 // field in the union.
 //
 // NativeTheme also supports getting the default size of a given part with
 // the GetPartSize() method.
-class NativeTheme {
+class UI_API NativeTheme {
  public:
   // The part to be painted / sized.
   enum Part {
     kCheckbox,
     kInnerSpinButton,
     kMenuList,
     kMenuCheck,
     kMenuCheckBackground,
     kMenuPopupArrow,
     kMenuPopupBackground,
@@ skipping 177 matching lines @@
   static unsigned int thumb_inactive_color_;
   static unsigned int thumb_active_color_;
   static unsigned int track_color_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeTheme);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_NATIVE_THEME_H_