Bug 52801 "Press F2 for focus" does not work for spell-checking hovers
"Press F2 for focus" does not work for spell-checking hovers.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
private CompositeActionGroup fContextMenuGroup;
	/**
	 * Holds the current occurrence annotations.
	 * @since 3.0
	 */
	private Annotation[] fOccurrenceAnnotations= null;
	/**
	 * Tells whether all occurrences of the element at the
	 * current caret location are automatically marked in
	 * this editor.
	 * @since 3.0
	 */
	private boolean fMarkOccurrenceAnnotations;
	/**
	 * Tells whether the occurrence annotations are sticky
	 * i.e. whether they stay even if there's no valid Java
	 * element at the current caret position.
	 * @since 3.0
	 */
	private boolean fStickyOccurrenceAnnotations;
	/**
	 * The internal shell activation listener for updating occurrences.
	 * @since 3.0
	 */
	private ActivationListener fActivationListener= new ActivationListener();
	private ISelectionListenerWithAST fPostSelectionListenerWithAST;
	private Job fOccurrencesFinderJob;
		
	/**
	 * Returns the most narrow java element including the given offset.