Bug 156883 [Viewers] enhancements to ILazyTreeContentProvider
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
* @param style
	 * @param rowIndex
	 * @return ViewerRow
	 */
	private ViewerRow createNewRowPart(ViewerRow parent, int style, int rowIndex) {
		if (parent == null) {
			if (rowIndex >= 0) {
				return getRowPartFromItem(new TreeItem(tree, style, rowIndex));
			}
			return getRowPartFromItem(new TreeItem(tree, style));
		}
		if (rowIndex >= 0) {
			return getRowPartFromItem(new TreeItem((TreeItem) parent.getItem(),
					SWT.NONE, rowIndex));
		}
		return getRowPartFromItem(new TreeItem((TreeItem) parent.getItem(),
				SWT.NONE));
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.AbstractTreeViewer#internalInitializeTree(org.eclipse.swt.widgets.Control)
	 */
	protected void internalInitializeTree(Control widget) {
		if (getContentProvider() instanceof ILazyTreeContentProvider) {
			ILazyTreeContentProvider lazyTreeContentProvider = (ILazyTreeContentProvider) getContentProvider();
			if (widget instanceof Tree && widget.getData() != null) {
				lazyTreeContentProvider.updateChildCount(widget.getData(), 0);
				return;
			}