Bug 52470 CallHierarchy: SourceLocation View doesn't deliver IJavaElement selection
M7 Steps: - Open Java Browsing Perspective - Open CallHierarchy - single-click on source location -> observe: JavaBrowsing Views lose their JavaElement I guess it's because there's no SelectionProviderMediator which delivers IJavaElements for selected source positions.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/CallHierarchyUI.java
* contains elements which are not MethodWrapper instances or not already IMember instances
     * they are discarded.  
     * @param selection The selection to convert.
     * @return An ISelection containing IMember's in place of MethodWrapper instances.
     */
    static ISelection convertSelection(ISelection selection) {
        if (selection.isEmpty()) {
            return selection;   
        }
        
        if (selection instanceof IStructuredSelection) {
            IStructuredSelection structuredSelection= (IStructuredSelection) selection;
            List javaElements= new ArrayList();
            for (Iterator iter= structuredSelection.iterator(); iter.hasNext();) {
                Object element= iter.next();
                if (element instanceof MethodWrapper) {
                    IMember member= ((MethodWrapper)element).getMember();
                    if (member != null) {
                        javaElements.add(member);
                    }
                } else if (element instanceof IMember) {
                    javaElements.add(element);
                }
            }
            return new StructuredSelection(javaElements);
        }
        return StructuredSelection.EMPTY; 
    }
}