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

ui/gfx/canvas.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_CANVAS_H_
 #define UI_GFX_CANVAS_H_
 #pragma once
 
 #include <string>
 
 #include "base/string16.h"
 // TODO(beng): remove this include when we no longer depend on SkTypes.
 #include "skia/ext/platform_canvas.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/ui_api.h"
 
 namespace ui {
 class Transform;
 
 typedef unsigned int TextureID;
 }
 
 namespace gfx {
 
 class Brush;
 class CanvasSkia;
 class Font;
 class Point;
 class Rect;
 
 // TODO(beng): documentation.
-class Canvas {
+class UI_API Canvas {
  public:
   // Specifies the alignment for text rendered with the DrawStringInt method.
   enum {
     TEXT_ALIGN_LEFT = 1,
     TEXT_ALIGN_CENTER = 2,
     TEXT_ALIGN_RIGHT = 4,
     TEXT_VALIGN_TOP = 8,
     TEXT_VALIGN_MIDDLE = 16,
     TEXT_VALIGN_BOTTOM = 32,
 
@@ skipping 180 matching lines @@
   // Create a texture ID that can be used for accelerated drawing.
   virtual ui::TextureID GetTextureID() = 0;
 
   // TODO(beng): remove this once we don't need to use any skia-specific methods
   //             through this interface.
   // A quick and dirty way to obtain the underlying SkCanvas.
   virtual CanvasSkia* AsCanvasSkia();
   virtual const CanvasSkia* AsCanvasSkia() const;
 };
 
-class CanvasPaint {
+class UI_API CanvasPaint {
  public:
   virtual ~CanvasPaint() {}
 
   // Creates a canvas that paints to |view| when it is destroyed. The canvas is
   // sized to the client area of |view|.
   static CanvasPaint* CreateCanvasPaint(gfx::NativeView view);
 
   // Returns true if the canvas has an invalid rect that needs to be repainted.
   virtual bool IsValid() const = 0;
 
   // Returns the rectangle that is invalid.
   virtual gfx::Rect GetInvalidRect() const = 0;
 
   // Returns the underlying Canvas.
   virtual Canvas* AsCanvas() = 0;
 };
 
 }  // namespace gfx;
 
 #endif  // UI_GFX_CANVAS_H_