Bug 158778 [Viewers] request for remove(parent, index) API on tree viewer
3.3 It would be helpful to have a 'remove(Object parent, int index)' method on the tree viewer to complement that 'replace(...)' and 'setChildCount(...)' APIs. The debug platform requires such a method to implement filtering in virtual tree views. Rather than performing a 'replace/remove' based on elements, the content provider can make one atomic call to remove an element at a specific index.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* @param listener
	 *            a tree viewer listener
	 */
	public void addTreeListener(ITreeViewerListener listener) {
		treeListeners.add(listener);
	}
	/**
	 * Adds the given SWT tree listener to the given SWT control.
	 * 
	 * @param control
	 *            the SWT control
	 * @param listener
	 *            the SWT tree listener
	 */
	protected abstract void addTreeListener(Control control,
			TreeListener listener);
	/*
	 * (non-Javadoc)
	 * 
	 * @see StructuredViewer#associate(Object, Item)
	 */
	protected void associate(Object element, Item item) {
		Object data = item.getData();
		if (data != null && data != element && equals(data, element)) {
			
			
			
			unmapElement(data, item);
			item.setData(element);
			mapElement(element, item);