Bug 75711 AstProvider should not create AST if requested by SelectionListenerWithASTManager
3.1 M2 If SelectionListenerWithASTManager waits for an AST and the editor closes we should not create an AST for that one but return null instead.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/OverrideIndicatorManager.java
else
							text= JavaEditorMessages.getFormattedString("OverrideIndicatorManager.overrides", qualifiedMethodName); 
						
						SimpleName name= node.getName();
						Position position= new Position(name.getStartPosition(), name.getLength());
						annotationMap.put(
								new OverrideIndicator(isImplements, text, binding.getKey()), 
								position);
					}
				}
				return false;
			}
		});
		
		if (progressMonitor.isCanceled())
			return;
		
		synchronized (fAnnotationModelLockObject) {
			if (fAnnotationModel instanceof IAnnotationModelExtension) {
				((IAnnotationModelExtension)fAnnotationModel).replaceAnnotations(fOverrideAnnotations, annotationMap);
			} else {
				removeAnnotations();
				Iterator iter= annotationMap.entrySet().iterator();
				while (iter.hasNext()) {
					Map.Entry mapEntry= (Map.Entry)iter.next(); 
					fAnnotationModel.addAnnotation((Annotation)mapEntry.getKey(), (Position)mapEntry.getValue());
				}
			}
			fOverrideAnnotations= (Annotation[])annotationMap.keySet().toArray(new Annotation[annotationMap.keySet().size()]);
		}