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
protected void addTreeListener(Control c, TreeListener listener) {
		((Tree) c).addTreeListener(listener);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.ColumnViewer#getColumnViewerOwner(int)
	 */
	protected Widget getColumnViewerOwner(int columnIndex) {
		if (columnIndex < 0 || ( columnIndex > 0 && columnIndex >= getTree().getColumnCount() ) ) {
			return null;
		}
		if (getTree().getColumnCount() == 0)
			return getTree();
		return getTree().getColumn(columnIndex);
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected Item[] getChildren(Widget o) {
		if (o instanceof TreeItem) {
			return ((TreeItem) o).getItems();
		}
		if (o instanceof Tree) {
			return ((Tree) o).getItems();
		}
		return null;
	}
	/*
	 * (non-Javadoc) Method declared in Viewer.