Issue 3985. Tweaks for warning messages

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 package com.google.dart.compiler.resolver;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.dart.compiler.DartCompilationError;
 import com.google.dart.compiler.DartCompilerContext;
 import com.google.dart.compiler.ErrorCode;
 import com.google.dart.compiler.ErrorSeverity;
@@ skipping 73 matching lines @@
     // Check for duplicate declaration in the enclosing scope.
     if (existingLocalElement == null && warningCode != null) {
       Element existingElement = scope.findElement(scope.getLibrary(), name);
       if (existingElement != null) {
         if (!Elements.isConstructorParameter(element)
             && !Elements.isParameterOfMethodWithoutBody(element)
             && !(Elements.isStaticContext(element) && !Elements.isStaticContext(existingElement))
             && !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);
           }
         }
       }
     }
     // Check for duplicate declaration in the same scope.
     if (existingLocalElement != null && errorCode != null) {
       SourceInfo nameSourceInfo = element.getNameLocation();
       String existingLocation = Elements.getRelativeElementLocation(element, existingLocalElement);
       onError(nameSourceInfo, errorCode, name, existingLocation);
     }
@@ skipping 314 matching lines @@
       String name = node.getName();
       return scope.findElement(scope.getLibrary(), name);
     }
 
     @Override
     public Element visitSyntheticErrorIdentifier(DartSyntheticErrorIdentifier node) {
       return Elements.dynamicElement();
     }
   }
 }