Remove last dependencies on ui/base from ui/gfx

ui/gfx/canvas_paint_gtk.h

Index: ui/gfx/canvas_paint_gtk.h
diff --git a/ui/gfx/canvas_paint_gtk.h b/ui/gfx/canvas_paint_gtk.h
index 889f30895b4726bf695a5559bf9f4d0652205540..649407a3c9d07cc9848cdc0339e09d7174c03455 100644
--- a/ui/gfx/canvas_paint_gtk.h
+++ b/ui/gfx/canvas_paint_gtk.h
@@ -17,7 +17,7 @@ namespace gfx {
 // On construction, it will set up a context for painting into, and on
 // destruction, it will commit it to the GdkWindow.
 // Note: The created context is always inialized to (0, 0, 0, 0).
-class UI_EXPORT CanvasSkiaPaint : public Canvas {
+class GFX_EXPORT CanvasSkiaPaint : public Canvas {
  public:
   // This constructor assumes the result is opaque.
   explicit CanvasSkiaPaint(GdkEventExpose* event);