Created _gtk_tree_view_column_request_width().

Removed gtk_tree_view_get_real_requested_width_from_column() from
gtktreeview.c in favor of this function in the treeviewcolumn domain
(since this function goes and checks treeviewcolumn internals, settings
and derives the real requested width, seems logical this should be done
by the treeviewcolumn instead).

gtk/gtktreeviewcolumn.c

@@ -1869,6 +1869,45 @@ gtk_tree_view_column_get_width (GtkTreeViewColumn *tree_column)
   return tree_column->priv->width;
 }
 
+gint
+_gtk_tree_view_column_request_width (GtkTreeViewColumn *tree_column)
+{
+  GtkTreeViewColumnPrivate *priv;
+  gint real_requested_width;
+
+  priv = tree_column->priv;
+
+  if (priv->use_resized_width)
+    {
+      real_requested_width = priv->resized_width;
+    }
+  else if (priv->column_type == GTK_TREE_VIEW_COLUMN_FIXED)
+    {
+      real_requested_width = priv->fixed_width;
+    }
+  else if (gtk_tree_view_get_headers_visible (GTK_TREE_VIEW (priv->tree_view)))
+    {
+      gint button_request;
+
+      gtk_widget_get_preferred_width (priv->button, &button_request, NULL);
+      real_requested_width = MAX (priv->requested_width, button_request);
+    }
+  else
+    {
+      real_requested_width = priv->requested_width;
+      if (real_requested_width < 0)
+        real_requested_width = 0;
+    }
+
+  if (priv->min_width != -1)
+    real_requested_width = MAX (real_requested_width, priv->min_width);
+
+  if (priv->max_width != -1)
+    real_requested_width = MIN (real_requested_width, priv->max_width);
+
+  return real_requested_width;
+}
+
 void
 _gtk_tree_view_column_allocate (GtkTreeViewColumn *tree_column,
 				int                x_offset,