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

ui/gfx/platform_font_win.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_PLATFORM_FONT_WIN_
 #define UI_GFX_PLATFORM_FONT_WIN_
 #pragma once
 
 #include "base/memory/ref_counted.h"
 #include "ui/gfx/platform_font.h"
+#include "ui/ui_api.h"
 
 namespace gfx {
 
-class PlatformFontWin : public PlatformFont {
+class UI_API PlatformFontWin : public PlatformFont {
  public:
   PlatformFontWin();
   explicit PlatformFontWin(const Font& other);
   explicit PlatformFontWin(NativeFont native_font);
   PlatformFontWin(const string16& font_name,
                   int font_size);
 
   // Dialog units to pixels conversion.
   // See http://support.microsoft.com/kb/145994 for details.
   int horizontal_dlus_to_pixels(int dlus) const {
@@ skipping 97 matching lines @@
   static HFontRef* base_font_ref_;
 
   // Indirect reference to the HFontRef, which references the underlying HFONT.
   scoped_refptr<HFontRef> font_ref_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_PLATFORM_FONT_WIN_