Bug 51653 [navigation] Quick Outline: Should also show interface members
I200402102000 We should consider showing the inherited members for interfaces at least when the target type is an interface itself.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/JavaOutlineInformationControl.java
private KeyAdapter fKeyAdapter;
	private OutlineContentProvider fOutlineContentProvider;
	private IJavaElement fInput= null;
	private AppearanceAwareLabelProvider fInnerLabelProvider;
	protected Color fForegroundColor;
	
	private class OutlineLabelProvider extends AppearanceAwareLabelProvider {