Bug 214621 [Viewers] Make ComboViewer non-final
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ComboViewer.java
* 
     * @see #ComboViewer(Combo)
     */
    private Combo combo;
    
    /**
     * This viewer's list control if this viewer is instantiated with a CCombo control; otherwise
     * <code>null</code>.
     * 
     * @see #ComboViewer(CCombo)
     * @since 3.3
     */
    private CCombo ccombo;
    /**
     * Creates a combo viewer on a newly-created combo control under the given parent.
     * The viewer has no input, no content provider, a default label provider, 
     * no sorter, and no filters.
     *
     * @param parent the parent control
     */
    public ComboViewer(Composite parent) {
        this(parent, SWT.READ_ONLY | SWT.BORDER);
    }
    /**
     * Creates a combo viewer on a newly-created combo control under the given parent.
     * The combo control is created using the given SWT style bits.
     * The viewer has no input, no content provider, a default label provider, 
     * no sorter, and no filters.
     *
     * @param parent the parent control