Bug 85452 [IDE] (regression) Backdrop missing when all perspectives closed
I20050215-2300 - close all perspectives - the main page is blank - it should have a backdrop with text and button explaining how to open a perspective
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/IDEWorkbenchAdvisor.java
private static final String WORKBENCH_PREFERENCE_CATEGORY_ID = "org.eclipse.ui.preferencePages.Workbench"; 
    /**
     * The dialog setting key to access the known installed features
     * since the last time the workbench was run.
     */
    private static final String INSTALLED_FEATURES = "installedFeatures"; 
    private static IDEWorkbenchAdvisor workbenchAdvisor = null;
    /**
     * Event loop exception handler for the advisor.
     */
    private IDEExceptionHandler exceptionHandler = null;
    /**
     * Contains the workspace location if the -showlocation command line
     * argument is specified, or <code>null</code> if not specified.
     */
    private String workspaceLocation = null;
    /**
     * Ordered map of versioned feature ids -> info that are new for this