2.4/user/src/com/google/gwt/user/client/ui/NativeHorizontalScrollbar.ui.xml

<!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent">
<ui:UiBinder
  xmlns:ui="urn:ui:com.google.gwt.uibinder"
  xmlns:g="urn:import:com.google.gwt.user.client.ui">

  <ui:style>
    .viewport {
    	position: relative;
    	overflow: hidden;
    }
    
    .scrollable {
    	position: absolute;
    	left: 0px;
    	bottom: 0px;
    	width: 100%;
    	height: 100px;
    	overflow: auto;
    	overflow-x: scroll;
    	overflow-y: hidden;
    }
    
    .content {
    	height: 1px;
    }
  </ui:style>

  <!-- Viewport: reveals only the scrollbar from the scrollable div. -->
  <div
    class="{style.viewport}">

    <!-- Scrollable: a scrollable div. -->
    <div
      ui:field="scrollable"
      class="{style.scrollable}">

      <!-- Content: controls how far the div can be scrolled. -->
      <div
        ui:field="contentDiv"
        class="{style.content}" />
    </div>
  </div>
</ui:UiBinder>