Bug 155650 [Preferences] Accessibility: Tab can't access to the "Forward to..." Split button on Preferences window
Steps to reproduce bug: 1.Launch Eclipse 3.2. 2.Goto Preferences window. 3.Select 'Java' (or anyother) on the left pane. 4.Then select 'Help' (or anyother) on the left pane. 5.Click the right-top split button 'Back to Java'. 6.Use Tab Key to access to navigate the control. DEFECT: Notice that you cannot navigate to the navigation-split button.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ToolBarManager.java
* <p>
	 * The default implementation of this framework method re-lays out the
	 * parent when the number of items crosses the zero threshold. Subclasses
	 * should override this method to implement their own re-layout strategy
	 * 
	 * @param layoutBar
	 *            the tool bar control
	 * @param oldCount
	 *            the old number of items
	 * @param newCount
	 *            the new number of items
	 */
	protected void relayout(ToolBar layoutBar, int oldCount, int newCount) {
		if ((oldCount == 0) != (newCount == 0)) {
			layoutBar.getParent().layout();
		}
	}
	/**
	 * Returns whether the tool bar control is created and not disposed.
	 * 
	 * @return <code>true</code> if the control is created and not disposed,
	 *         <code>false</code> otherwise
	 */
	private boolean toolBarExist() {
		return toolBar != null && !toolBar.isDisposed();
	}
	/*
	 * (non-Javadoc) Method declared on IContributionManager.
	 */
	public void update(boolean force) {