Bug 193231 RCP designer does not display Preview tab and View menu.
On RCP designer, Preview tab is missing and View Report menus. Please check the attached screen shot for detail.
viewer/org.eclipse.birt.report.viewer/src/org/eclipse/birt/report/viewer/utilities/WebViewer.java
final public static String DOC = "doc"; 
	/**
	 * Birt web viewer plugin id
	 */
	final public static String WebAppPlugin = ViewerPlugin.PLUGIN_ID;
	/**
	 * locale preference name
	 */
	final public static String USER_LOCALE = "user_locale"; 
	/**
	 * Preference key for SVG chart flag.
	 */
	final public static String SVG_FLAG = "svg_flag"; 
	/**
	 * Preference key for master page content flag.
	 */
	final public static String MASTER_PAGE_CONTENT = "master_page_content"; 
	
	final public static String PREVIEW_MAXROW = "preview_maxrow"; 
	
	/**
	 * Key to indicate the format of the preview.
	 */
	public final static String FORMAT_KEY = "FORMAT_KEY"; 
	/**
	 * Key to indicate the 'allowPage' control of the preview.
	 */
	public final static String ALLOW_PAGE_KEY = "ALLOW_PAGE_KEY"; 
	/**
	 * Key to indicate the 'servletName' of the preview.