Base JavaScript code position computation on JavaScript tracer.

pkg/compiler/lib/src/js_emitter/lazy_emitter/model_emitter.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.
 
 library dart2js.js_emitter.lazy_emitter.model_emitter;
 
 import '../../compiler.dart' show
     Compiler;
 import '../../constants/values.dart' show
     ConstantValue,
@@ skipping 141 matching lines @@
     }).toList();
 
     js.Statement mainAst = emitMainFragment(program);
 
     js.TokenCounter counter = new js.TokenCounter();
     fragmentsCode.forEach(counter.countTokens);
     counter.countTokens(mainAst);
 
     program.finalizers.forEach((js.TokenFinalizer f) => f.finalizeTokens());
 
+    // TODO(johnnniwinther): Support source maps in this emitter.
     for (int i = 0; i < fragmentsCode.length; ++i) {
-      String code = js.prettyPrint(fragmentsCode[i], compiler).getText();
+      String code = js.createCodeBuffer(fragmentsCode[i], compiler).getText();
       totalSize += code.length;
       compiler.outputProvider(fragments[i+1].outputFileName, deferredExtension)
         ..add(code)
         ..close();
     }
 
-    String mainCode = js.prettyPrint(mainAst, compiler).getText();
+    String mainCode = js.createCodeBuffer(mainAst, compiler).getText();
     compiler.outputProvider(mainFragment.outputFileName, 'js')
         ..add(buildGeneratedBy(compiler))
         ..add(mainCode)
         ..close();
     totalSize += mainCode.length;
 
     return totalSize;
   }
 
   /// Returns a [js.Literal] that represents the string result of unparsing
@@ skipping 1068 matching lines @@
 
   var end = Date.now();
   // print('Setup: ' + (end - start) + ' ms.');
 
   #invokeMain;  // Start main.
 
 })(Date.now(), #code)
 }""";
 
 }