Bug 90528 Editor icon does not show problem decoration for second instance
3.1 M6 - open a .java file that has errors or warnings - the editor tab icon has the problem decoration - Window > New Window - open the same file in the new window - the editor tab icon is missing the problem decoration
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
private GenerateActionGroup fGenerateActionGroup;
	private CompositeActionGroup fContextMenuGroup;
	
	/**
	 * Reconciling listeners.
	 * @since 3.0
	 */
	private ListenerList fReconcilingListeners= new ListenerList();
	/**
	 * Mutex for the reconciler. See https://bugs.eclipse.org/bugs/show_bug.cgi?id=63898
	 * for a description of the problem.
	 * <p>
	 * TODO remove once the underlying problem (https://bugs.eclipse.org/bugs/show_bug.cgi?id=66176) is solved.
	 * </p>
	 */
	private final Object fReconcilerLock= new Object();
	
	
	/**
	 * Creates a new compilation unit editor.
	 */
	public CompilationUnitEditor() {
		super();
		setDocumentProvider(JavaPlugin.getDefault().getCompilationUnitDocumentProvider());
		setEditorContextMenuId("#CompilationUnitEditorContext"); 
		setRulerContextMenuId("#CompilationUnitRulerContext"); 
		setOutlinerContextMenuId("#CompilationUnitOutlinerContext"); 
		
		fSavePolicy= null;