docs: Use gtk_widget_get_preferred_size() instead gtk_size_request_get_preferred_size()

GtkSizeRequest interface is now merged in GtkWidget

docs/reference/gtk/tmpl/gtkcontainer.sgml

@@ -58,7 +58,7 @@ of their children.
 <para>
 The size requisition phase of the widget layout process operates top-down.
 It starts at a top-level widget, typically a #GtkWindow. The top-level widget
-asks its child for its size requisition by calling gtk_size_request_get_preferred_size().
+asks its child for its size requisition by calling gtk_widget_get_preferred_size().
 To determine its requisition, the child asks its own children for their
 requisitions and so on. Finally, the top-level widget will get a requisition
 back from its child.

docs/reference/gtk/tmpl/gtkfilechooserbutton.sgml

@@ -37,7 +37,7 @@ The #GtkFileChooserButton supports the #GtkFileChooserAction<!--
 <para>
 The #GtkFileChooserButton will ellipsize the label,
 and thus will thus request little horizontal space.  To give the button
-more space, you should call gtk_size_request_get_preferred_size(),
+more space, you should call gtk_widget_get_preferred_size(),
 gtk_file_chooser_button_set_width_chars(), or pack the button in
 such a way that other interface elements give space to the widget.
 </para>

gtk/gtk.symbols

@@ -370,7 +370,6 @@ gtk_scroll_type_get_type G_GNUC_CONST
 gtk_selection_mode_get_type G_GNUC_CONST
 gtk_shadow_type_get_type G_GNUC_CONST
 gtk_size_group_mode_get_type G_GNUC_CONST
-gtk_size_request_mode_get_type G_GNUC_CONST
 gtk_sort_type_get_type G_GNUC_CONST
 gtk_spin_type_get_type G_GNUC_CONST
 gtk_state_type_get_type G_GNUC_CONST

gtk/gtkwidget.c

@@ -8653,7 +8653,7 @@ gtk_widget_set_size_request (GtkWidget *widget,
  * @height indicates that that dimension has not been set explicitly
  * and the natural requisition of the widget will be used intead. See
  * gtk_widget_set_size_request(). To get the size a widget will
- * actually request, call gtk_size_request_get_preferred_size() instead of
+ * actually request, call gtk_widget_get_preferred_size() instead of
  * this function.
  **/
 void

gtk/gtkwindow.c

@@ -6503,7 +6503,7 @@ gtk_window_constrain_size (GtkWindow   *window,
 
 /* Compute the set of geometry hints and flags for a window
  * based on the application set geometry, and requisition
- * of the window. gtk_size_request_get_preferred_size() must have been
+ * of the window. gtk_widget_get_preferred_size() must have been
  * called first.
  */
 static void