sizerequest: Cache sizes without size groups

We compute on-demand for size groups anyway, so we can (in theory, this
patch doesn't do that yet) get around costly cache blowing when
invalidating single widgets of a size group this way.

gtk/gtksizerequest.c

@@ -464,15 +464,6 @@ compute_size_for_orientation (GtkWidget         *widget,
           nat_size = adjusted_natural;
         }
 
-      /* Update size-groups with our request and update our cached requests
-       * with the size-group values in a single pass.
-       */
-      _gtk_size_group_bump_requisition (widget,
-					orientation,
-                                        for_size,
-					&min_size,
-					&nat_size);
-
       commit_cached_size (widget, orientation, for_size, min_size, nat_size);
     }
   else
@@ -481,6 +472,12 @@ compute_size_for_orientation (GtkWidget         *widget,
       nat_size = cached_size->natural_size;
     }
 
+  _gtk_size_group_bump_requisition (widget,
+                                    orientation,
+                                    for_size,
+                                    &min_size,
+                                    &nat_size);
+
   if (minimum_size)
     *minimum_size = min_size;