Bug 45638 [preferences] overwrite mode setting
Needs to be moved to Java>Editor>Typing.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/JavaEditorPreferencePage.java
* @see PreferencePage#performDefaults()
	 */
	protected void performDefaults() {
		
		fOverlayStore.loadDefaults();
		initializeFields();
		handleSyntaxColorListSelection();
		handleAppearanceColorListSelection();
		handleAnnotationListSelection();
		handleContentAssistColorListSelection();
		fJavaEditorHoverConfigurationBlock.performDefaults();		
		super.performDefaults();
		fPreviewViewer.invalidateTextPresentation();
	}
	
	/*
	 * @see DialogPage#dispose()
	 */
	public void dispose() {
		
		if (fJavaTextTools != null) {
			fJavaTextTools.dispose();
			fJavaTextTools= null;
		}
		
		if (fOverlayStore != null) {
			fOverlayStore.stop();
			fOverlayStore= null;
		}
		if (fBackgroundColor != null && !fBackgroundColor.isDisposed())