set error hint title (IDEA-157821)

java/java-impl/src/com/intellij/refactoring/extractclass/ExtractClassHandler.java

@@ -63,7 +63,7 @@ public class ExtractClassHandler implements ElementsHandler {
     if (cannotRefactorMessage != null)  {
       CommonRefactoringUtil.showErrorHint(project, editor, 
                                           RefactorJBundle.message("cannot.perform.the.refactoring") + cannotRefactorMessage, 
-                                          null, getHelpID());
+                                          ExtractClassProcessor.REFACTORING_NAME, getHelpID());
       return;
     }
     new ExtractClassDialog(containingClass, selectedMember).show();

java/java-impl/src/com/intellij/refactoring/extractclass/ExtractClassProcessor.java

@@ -66,6 +66,7 @@ import java.util.*;
 
 public class ExtractClassProcessor extends FixableUsagesRefactoringProcessor {
   private static final Logger logger = Logger.getInstance("com.siyeh.rpp.extractclass.ExtractClassProcessor");
+  @NonNls public static final String REFACTORING_NAME = "Extract Delegate";
 
   private final PsiClass sourceClass;
   private final List<PsiField> fields;