Add a "librarySource" field to CompilationUnitElementImpl.

pkg/analyzer/lib/src/generated/testing/element_factory.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.testing.element_factory;
 
 import 'dart:collection';
@@ skipping 64 matching lines @@
     ClassElementImpl element =
         classElement(typeName, superclassType, parameterNames);
     element.typedef = true;
     return element;
   }
 
   static ClassElementImpl classTypeAlias2(String typeName,
           [List<String> parameterNames]) =>
       classTypeAlias(typeName, objectType, parameterNames);
 
-  static CompilationUnitElementImpl compilationUnit(String fileName) {
+  static CompilationUnitElementImpl compilationUnit(String fileName,
+      [Source librarySource]) {
     Source source = new NonExistingSource(fileName, UriKind.FILE_URI);
     CompilationUnitElementImpl unit = new CompilationUnitElementImpl(fileName);
     unit.source = source;
+    if (librarySource == null) {
+      librarySource = source;
+    }
+    unit.librarySource = librarySource;
     return unit;
   }
 
   static ConstLocalVariableElementImpl constLocalVariableElement(String name) =>
       new ConstLocalVariableElementImpl(name, 0);
 
   static ConstructorElementImpl constructorElement(
       ClassElement definingClass, String name, bool isConst,
       [List<DartType> argumentTypes]) {
     DartType type = definingClass.type;
@@ skipping 424 matching lines @@
       setter.variable = variable;
       setter.parameters =
           <ParameterElement>[requiredParameter2("_$name", type)];
       setter.returnType = VoidTypeImpl.instance;
       setter.type = new FunctionTypeImpl.con1(setter);
       variable.setter = setter;
     }
     return variable;
   }
 }