Bug 17423 Revert apears twice in the popup menu.
Build F1. 1) Open a java editor. 2) Popup the menu. There is only one Revert option disable as it should be. 3) Make the editor dirty. 4) Popup the menu. There are two Revert option in the menu. One after UNDO and other before FORMAT.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
Control control= getControl();
			if (control instanceof Composite) {
				Composite composite= (Composite) control;
				composite.layout();
			}
		}
		
		public void showOverviewRuler() {
			fIsOverviewRulerVisible= true;
			Control control= getControl();
			if (control instanceof Composite) {
				Composite composite= (Composite) control;
				composite.layout();
			}
		}
		
		public boolean isOverviewRulerVisible() {
			return fIsOverviewRulerVisible;
		}
		
		/*
		 * @see ISourceViewer#setDocument(IDocument, IAnnotationModel, int, int)
		 */
		public void setDocument(IDocument document, IAnnotationModel annotationModel, int visibleRegionOffset, int visibleRegionLength) {
			super.setDocument(document, annotationModel, visibleRegionOffset, visibleRegionLength);
			fOverviewRuler.setModel(annotationModel);
		}
	};
	
	static class TabConverter implements ITextConverter {