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

ui/gfx/gdi_util.h

 // Copyright (c) 2009 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_GDI_UTIL_H_
 #define UI_GFX_GDI_UTIL_H_
 #pragma once
 
 #include <vector>
 #include <windows.h>
 
 #include "ui/gfx/rect.h"
+#include "ui/ui_api.h"
 
 namespace gfx {
 
 // Creates a BITMAPINFOHEADER structure given the bitmap's size.
-void CreateBitmapHeader(int width, int height, BITMAPINFOHEADER* hdr);
+UI_API void CreateBitmapHeader(int width, int height, BITMAPINFOHEADER* hdr);
 
 // Creates a BITMAPINFOHEADER structure given the bitmap's size and
 // color depth in bits per pixel.
 void CreateBitmapHeaderWithColorDepth(int width, int height, int color_depth,
                                       BITMAPINFOHEADER* hdr);
 
 // Creates a BITMAPV4HEADER structure given the bitmap's size.  You probably
 // only need to use BMP V4 if you need transparency (alpha channel). This
 // function sets the AlphaMask to 0xff000000.
-void CreateBitmapV4Header(int width, int height, BITMAPV4HEADER* hdr);
+UI_API void CreateBitmapV4Header(int width, int height, BITMAPV4HEADER* hdr);
 
 // Creates a monochrome bitmap header.
 void CreateMonochromeBitmapHeader(int width, int height, BITMAPINFOHEADER* hdr);
 
 // Modify the given hrgn by subtracting the given rectangles.
-void SubtractRectanglesFromRegion(HRGN hrgn,
-                                  const std::vector<gfx::Rect>& cutouts);
+UI_API void SubtractRectanglesFromRegion(HRGN hrgn,
+                                         const std::vector<gfx::Rect>& cutouts);
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GDI_UTIL_H_