Bug 166001 The webpage can't be found in WebView, if "WebViewer.startup( null );" is not called.
Now I'm using a SVG viewer to preview report in designer, it need not a HTTP server. So I removed "WebViewer.startup( null );" from designer's initial process, but I found those "web view as ..." all can not open a web page.
viewer/org.eclipse.birt.report.viewer/src/org/eclipse/birt/report/viewer/utilities/WebViewer.java
* @param report
	 *            report file name
	 * @param params
	 *            report parameter map
	 * @return valid web viewer url
	 */
	private static String createURL( String report, Map params )
	{
		if ( params == null || params.isEmpty( ) )
			return createURL( null, report, null, true, null, null );
		String servletName = (String) params.get( SERVLET_NAME_KEY );
		String format = (String) params.get( FORMAT_KEY );
		String resourceFolder = (String) params.get( RESOURCE_FOLDER_KEY );
		Boolean allowPage = (Boolean) params.get( ALLOW_PAGE_KEY );
		if ( PDF.equalsIgnoreCase( format ) )
		{
			servletName = "run"; 
		}
		else
		{
			if ( servletName == null || servletName.trim( ).length( ) <= 0 )
			{
				if ( allowPage == null )
					servletName = "frameset"; 
				else
				{
					servletName = allowPage.booleanValue( )
							? "frameset" : "run"; 
				}
			}