Bug 174701 [Viewers] ViewerRow should be reused instead of connected to the Item
Currently we create a ViewerRow ver every Item we create this can degrade performance, we should cache the row and reuse it
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected Item[] getItems(Item item) {
		return ((TreeItem) item).getItems();
	}
	/**
	 * The tree viewer implementation of this <code>Viewer</code> framework
	 * method ensures that the given label provider is an instance of either
	 * <code>ITableLabelProvider</code> or <code>ILabelProvider</code>. If
	 * it is an <code>ITableLabelProvider</code>, then it provides a separate
	 * label text and image for each column. If it is an
	 * <code>ILabelProvider</code>, then it provides only the label text and
	 * image for the first column, and any remaining columns are blank.
	 */
	public IBaseLabelProvider getLabelProvider() {
		return super.getLabelProvider();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected Item getParentItem(Item item) {
		return ((TreeItem) item).getParentItem();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected Item[] getSelection(Control widget) {
		return ((Tree) widget).getSelection();
	}