/indra/newview/skins/default/xui/en/widgets/expandable_text.xml

<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
<expandable_text
 max_height="300" >
 <textbox
  parse_urls="true"
  allow_scroll="true"
  bg_visible="false"
  follows="left|top|right"
  name="text"
  read_only="true"
  use_ellipses="true"
  word_wrap="true"
  show_context_menu="true"
  tab_stop="true"
  v_pad="3"
  h_pad="4" >
 </textbox>
 <scroll
  name="scroll"
  follows="all"
 />
</expandable_text>