pjs/toolkit/content/widgets/toolbarbutton.xml

<?xml version="1.0"?>

<bindings id="toolbarbuttonBindings"
   xmlns="http://www.mozilla.org/xbl"
   xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
   xmlns:xbl="http://www.mozilla.org/xbl">

  <binding id="toolbarbutton" display="xul:button"
           extends="chrome://global/content/bindings/button.xml#button-base">
    <resources>
      <stylesheet src="chrome://global/skin/toolbarbutton.css"/>
    </resources>
    
    <content>
      <children includes="observes|template|menupopup|tooltip"/>
      <xul:image class="toolbarbutton-icon" xbl:inherits="validate,src=image,toolbarmode,buttonstyle"/>
      <xul:label class="toolbarbutton-text" crop="right" flex="1"
                 xbl:inherits="value=label,accesskey,crop,toolbarmode,buttonstyle"/>
    </content>
  </binding>

  <binding id="menu" display="xul:menu" 
           extends="chrome://global/content/bindings/toolbarbutton.xml#toolbarbutton">
    <content>
      <children includes="observes|template|menupopup|tooltip"/>
      <xul:image class="toolbarbutton-icon" xbl:inherits="validate,src=image,toolbarmode,buttonstyle"/>
      <xul:label class="toolbarbutton-text" crop="right" flex="1"
                 xbl:inherits="value=label,accesskey,crop,dragover-top,toolbarmode,buttonstyle"/>
      <xul:dropmarker type="menu" class="toolbarbutton-menu-dropmarker" xbl:inherits="disabled"/>
    </content>
  </binding>
  
  <binding id="menu-orient" display="xul:menu"
           extends="chrome://global/content/bindings/toolbarbutton.xml#toolbarbutton">
    <content>
      <children includes="observes|template|menupopup|tooltip"/>
      <xul:hbox flex="1" align="center">
        <xul:box xbl:inherits="orient" flex="1" align="center">
          <xul:image class="toolbarbutton-icon" xbl:inherits="validate,src=image,toolbarmode,buttonstyle"/>
          <xul:label class="toolbarbutton-text" crop="right" flex="1"
                    xbl:inherits="value=label,accesskey,crop,dragover-top,toolbarmode,buttonstyle"/>
        </xul:box>
        <xul:dropmarker type="menu" class="toolbarbutton-menu-dropmarker" xbl:inherits="disabled"/>
      </xul:hbox>
    </content>
  </binding>
  
  <binding id="menu-button" display="xul:menu" 
           extends="chrome://global/content/bindings/button.xml#menu-button-base">
    <resources>
      <stylesheet src="chrome://global/skin/toolbarbutton.css"/>
    </resources>

    <content>
      <children includes="observes|template|menupopup|tooltip"/>
      <xul:toolbarbutton class="box-inherit toolbarbutton-menubutton-button"
                         anonid="button" flex="1" allowevents="true"
                         xbl:inherits="disabled,crop,image,label,accesskey,command,
                                       align,dir,pack,orient,toolbarmode,buttonstyle"/>
      <xul:dropmarker type="menu-button" class="toolbarbutton-menubutton-dropmarker"
                      xbl:inherits="align,dir,pack,orient,disabled,toolbarmode,buttonstyle"/>
    </content>
  </binding>
  
  
  <binding id="toolbarbutton-image"
           extends="chrome://global/content/bindings/toolbarbutton.xml#toolbarbutton">
    <content>
      <xul:image class="toolbarbutton-icon" xbl:inherits="src=image"/>
    </content>
  </binding>
  
  <binding id="dropmarker">
    <content>
      <xul:image class="menubutton-dropmarker-icon"/>
    </content>

    <implementation implements="nsIAccessibleProvider">
      <property name="accessible">
        <getter>
          <![CDATA[
            var accService = Components.classes["@mozilla.org/accessibilityService;1"].getService(Components.interfaces.nsIAccessibilityService);
            return accService.createXULDropmarkerAccessible(this);
          ]]>
        </getter>
      </property>
    </implementation>
  </binding>
    
</bindings>