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

ui/gfx/gtk_preserve_window.h

Index: ui/gfx/gtk_preserve_window.h
===================================================================
--- ui/gfx/gtk_preserve_window.h	(revision 92815)
+++ ui/gfx/gtk_preserve_window.h	(working copy)
@@ -9,6 +9,8 @@
 #include <gdk/gdk.h>
 #include <gtk/gtk.h>
 
+#include "ui/ui_api.h"
+
 // GtkFixed creates an X window when realized and destroys an X window
 // when unrealized. GtkPreserveWindow allows overrides this
 // behaviour. When preserve is set (via gtk_preserve_window_set_preserve),
@@ -45,7 +47,7 @@
 };
 
 GType gtk_preserve_window_get_type() G_GNUC_CONST;
-GtkWidget* gtk_preserve_window_new();
+UI_API GtkWidget* gtk_preserve_window_new();
 
 // Whether or not we should preserve associated windows as the widget
 // is realized or unrealized.
@@ -56,8 +58,8 @@
 // Whether or not someone else will gdk_window_resize the GdkWindow associated
 // with this widget (needed by the GPU process to synchronize resizing
 // with swapped between front and back buffer).
-void gtk_preserve_window_delegate_resize(GtkPreserveWindow* widget,
-                                         gboolean delegate);
+UI_API void gtk_preserve_window_delegate_resize(GtkPreserveWindow* widget,
+                                                gboolean delegate);
 
 G_END_DECLS