Bug 23459 add preference option to turn off variable guessing on method completion
request from Adam
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/JavaEditorPreferencePage.java
fOverlayStore.propagate();
		JavaPlugin.getDefault().savePluginPreferences();
		return true;
	}
	
	/*
	 * @see PreferencePage#performDefaults()
	 */
	protected void performDefaults() {
		
		fFontEditor.loadDefault();
		
		fOverlayStore.loadDefaults();
		initializeFields();
		handleSyntaxColorListSelection();
		handleAppearanceColorListSelection();
		super.performDefaults();
		
		fPreviewViewer.invalidateTextPresentation();
	}
	
	/*
	 * @see DialogPage#dispose()
	 */
	public void dispose() {
		
		if (fJavaTextTools != null) {
			fJavaTextTools= null;
		}