Update only unique references during rename refactoring.

editor/tools/plugins/com.google.dart.engine.services_test/src/com/google/dart/engine/services/internal/refactoring/RenameRefactoringImplTest.java

Index: editor/tools/plugins/com.google.dart.engine.services_test/src/com/google/dart/engine/services/internal/refactoring/RenameRefactoringImplTest.java
diff --git a/editor/tools/plugins/com.google.dart.engine.services_test/src/com/google/dart/engine/services/internal/refactoring/RenameRefactoringImplTest.java b/editor/tools/plugins/com.google.dart.engine.services_test/src/com/google/dart/engine/services/internal/refactoring/RenameRefactoringImplTest.java
index 9519e2bad35796915d123ee4fdf17cada2a77c66..cfb6629ce913b6cd23f0938f03aa19991a160db2 100644
--- a/editor/tools/plugins/com.google.dart.engine.services_test/src/com/google/dart/engine/services/internal/refactoring/RenameRefactoringImplTest.java
+++ b/editor/tools/plugins/com.google.dart.engine.services_test/src/com/google/dart/engine/services/internal/refactoring/RenameRefactoringImplTest.java
@@ -14,18 +14,63 @@
 
 package com.google.dart.engine.services.internal.refactoring;
 
+import com.google.dart.engine.AnalysisEngine;
+import com.google.dart.engine.ast.CompilationUnit;
 import com.google.dart.engine.ast.SimpleIdentifier;
+import com.google.dart.engine.context.AnalysisContext;
+import com.google.dart.engine.context.ChangeSet;
 import com.google.dart.engine.element.Element;
+import com.google.dart.engine.element.LibraryElement;
 import com.google.dart.engine.services.change.Change;
 import com.google.dart.engine.services.refactoring.RefactoringFactory;
 import com.google.dart.engine.services.refactoring.RenameRefactoring;
 import com.google.dart.engine.services.status.RefactoringStatusSeverity;
+import com.google.dart.engine.source.DartUriResolver;
+import com.google.dart.engine.source.FileBasedSource;
+import com.google.dart.engine.source.Source;
+import com.google.dart.engine.source.SourceFactory;
+import com.google.dart.engine.utilities.io.FileUtilities2;
 
 /**
  * Abstract test for testing {@link RenameRefactoring}s.
  */
 public abstract class RenameRefactoringImplTest extends RefactoringImplTest {
+  /**
+   * Helper for creating and analyzing separate {@link AnalysisContext}s.
+   */
+  protected final class ContextHelper {
+    public final AnalysisContext context;
+    public final SourceFactory sourceFactory;
+
+    public ContextHelper() {
+      context = newAnalysisContext();
+      sourceFactory = context.getSourceFactory();
+    }
+
+    public Source addSource(String path, String code) {
+      Source source = new FileBasedSource(
+          sourceFactory.getContentCache(),
+          FileUtilities2.createFile(path));
+      // add source
+      {
+        sourceFactory.setContents(source, "");
+        ChangeSet changeSet = new ChangeSet();
+        changeSet.added(source);
+        context.applyChanges(changeSet);
+      }
+      // update source
+      context.setContents(source, code);
+      return source;
+    }
+
+    public CompilationUnit analyzeSingleUnitLibrary(Source source) throws Exception {
+      LibraryElement libraryElement = context.computeLibraryElement(source);
+      return context.resolveCompilationUnit(source, libraryElement);
+    }
+  }
+
   protected RenameRefactoring refactoring;
+
   protected Change refactoringChange;
 
   /**
@@ -67,4 +112,14 @@ public abstract class RenameRefactoringImplTest extends RefactoringImplTest {
     Element element = findIdentifierElement(search);
     createRenameRefactoring(element);
   }
+
+  /**
+   * @return new {@link AnalysisContext} with SDK.
+   */
+  protected final AnalysisContext newAnalysisContext() {
+    AnalysisContext context = AnalysisEngine.getInstance().createAnalysisContext();
+    SourceFactory sourceFactory = new SourceFactory(new DartUriResolver(defaultSdk));
+    context.setSourceFactory(sourceFactory);
+    return context;
+  }
 }