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/AbstractTableViewer.java
public void replace(Object element, int index) {
		Item item = doGetItem(index);
		refreshItem(item, element);
	}
	/**
	 * Clear the table item at the specified index
	 * 
	 * @param index
	 *            the index of the table item to be cleared
	 * 
	 * @since 3.1
	 */
	public void clear(int index) {
		Item item = doGetItem(index);
		if (item.getData() != null) {
			disassociate(item);
		}
		doClear(index);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.StructuredViewer#getRawChildren(java.lang.Object)
	 */
	protected Object[] getRawChildren(Object parent) {
		Assert.isTrue(!(getContentProvider() instanceof ILazyContentProvider),
				"Cannot get raw children with an ILazyContentProvider");
		return super.getRawChildren(parent);
	}
	/*