Bug 181061 [Viewers] JFace viewers performance issues in 3.3
A number of the JFace performance tests are red since I20060926-0800.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTableViewer.java
if (item.isDisposed()) {
					unmapElement(element, item);
					return;
				}
			}
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.ColumnViewer#getColumnViewerOwner(int)
	 */
	protected Widget getColumnViewerOwner(int columnIndex) {
		if (columnIndex < 0
				|| (columnIndex > 0 && columnIndex >= doGetColumnCount())) {
			return null;
		}
		if (doGetColumnCount() == 0)
			return getControl();
		return doGetColumn(columnIndex);
	}
	/**
	 * Returns the element with the given index from this table viewer. Returns
	 * <code>null</code> if the index is out of range.
	 * <p>
	 * This method is internal to the framework.
	 * </p>
	 *