 message history changes; for example, when there is a new message
  or the messages are cleared.</td>
</tr>
<tr>
<td colspan="2" class="idxrow"><a onclick="javascript:loadClassListFrame('com/adobe/rtc/events/class-list.html');" href="com/adobe/rtc/events/ChatEvent.html#HISTORY_CHANGE">HISTORY_CHANGE</a> &mdash; Constant static property in class com.adobe.rtc.events.<a onclick="javascript:loadClassListFrame('com/adobe/rtc/events/class-list.html');" href="com/adobe/rtc/events/ChatEvent.html">ChatEvent</a></t