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/TreeViewer.java
*            the SWT style bits used to create the tree.
	 */
	public TreeViewer(Composite parent, int style) {
		this(new Tree(parent, style));
	}
	/**
	 * Creates a tree viewer on the given tree control. The viewer has no input,
	 * no content provider, a default label provider, no sorter, and no filters.
	 * 
	 * @param tree
	 *            the tree control
	 */
	public TreeViewer(Tree tree) {
		super();
		this.tree = tree;
		hookControl(tree);
		treeEditor = new TreeEditor(tree);
		initTreeViewerImpl();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected void addTreeListener(Control c, TreeListener listener) {
		((Tree) c).addTreeListener(listener);
	}
	/**
	 * Cancels a currently active cell editor. All changes already done in the
	 * cell editor are lost.
	 * 
	 * @since 3.1