Upon further review, LanguageServiceManager can return multiple instances of IEditorService. We need to add these methods to a service which has only one instance per language, or create a new service.
*** NEW Proposed IMP API change: ***
Create a new service with the following methods:
public interface IEditorInputService{
public IFile getFile(IEditorInput editorInput);
public String getNameExtension(IEditorInput editorInput);