Issue 3985. Tweaks for warning messages

compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java

Index: compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
diff --git a/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java b/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
index 61a25f393099afdb3e58a6264d79d5c727626504..69bfd943940ca986a234b93dc3e9eadd98f0fe53 100644
--- a/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
+++ b/compiler/java/com/google/dart/compiler/resolver/ResolutionContext.java
@@ -91,11 +91,12 @@ public class ResolutionContext implements ResolutionErrorListener {
             && !existingElement.getModifiers().isAbstractField()
             && !Elements.isArtificialAssertMethod(existingElement)) {
           SourceInfo nameSourceInfo = element.getNameLocation();
+          String existingTitle = Elements.getUserElementTitle(existingElement);
           String existingLocation = Elements.getRelativeElementLocation(element, existingElement);
           if (existingElement.getKind() == ElementKind.LIBRARY_PREFIX) {
             onError(nameSourceInfo, ResolverErrorCode.CANNOT_HIDE_IMPORT_PREFIX, name);
           } else {
-            onError(nameSourceInfo, warningCode, name, existingElement, existingLocation);
+            onError(nameSourceInfo, warningCode, name, existingTitle, existingLocation);
           }
         }
       }