Make SourceInfo a class, rename its menthods.

compiler/java/com/google/dart/compiler/ast/viz/TextWriter.java

 // Copyright (c) 2011, 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.ast.viz;
 
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
 
 import com.google.common.io.Closeables;
 import com.google.dart.compiler.ast.DartUnit;
 
 /**
  * Write the AST in Text format. Output file is placed next to the JS file in the output directory
  */
 public class TextWriter extends ConsoleWriter {
 
   public TextWriter(String outputDir) {
     super(outputDir);
   }
 
   @Override
   protected void startHook(DartUnit unit) {
     if (!isIgnored(unit)) {
-      String txtFilePath = outputDir + File.separator + unit.getSource().getUri()
+      String txtFilePath = outputDir + File.separator + unit.getSourceInfo().getSource().getUri()
           + ".ast.txt";
       makeParentDirs(txtFilePath);
       try {
         //Set output to text file
         out = new FileWriter(new File(txtFilePath));
       } catch (IOException e) {
         e.printStackTrace();
       }
     }
   }
 
   @Override
   protected void endHook(DartUnit unit) {
     if (!isIgnored(unit)) {
       try {
         Closeables.close(out, true);
       } catch (IOException e) {
         System.err.println("Error closing AST output file");
         e.printStackTrace();
       }
     }
   }
 }