Fix issue 19424

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/scope/Scope.java

 /*
  * Copyright (c) 2012, the Dart project authors.
  * 
  * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  * 
  * http://www.eclipse.org/legal/epl-v10.html
  * 
  * Unless required by applicable law or agreed to in writing, software distributed under the License
  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
@@ skipping 160 matching lines @@
    */
   protected abstract AnalysisErrorListener getErrorListener();
 
   /**
    * Return the source that contains the given identifier, or the source associated with this scope
    * if the source containing the identifier could not be determined.
    * 
    * @param identifier the identifier whose source is to be returned
    * @return the source that contains the given identifier
    */
-  protected final Source getSource(AstNode node) {
+  protected Source getSource(AstNode node) {
     CompilationUnit unit = node.getAncestor(CompilationUnit.class);
     if (unit != null) {
       CompilationUnitElement unitElement = unit.getElement();
       if (unitElement != null) {
         return unitElement.getSource();
       }
     }
     return null;
   }
 
@@ skipping 37 matching lines @@
   private String getName(Element element) {
     if (element instanceof MethodElement) {
       MethodElement method = (MethodElement) element;
       if (method.getName().equals("-") && method.getParameters().length == 0) {
         return UNARY_MINUS;
       }
     }
     return element.getName();
   }
 }