Updated the schema of the yaml output.

pkg/docgen/lib/dart2yaml.dart

 // Copyright (c) 2013, 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 library is used to convert data from a map to a YAML string.
  */
 library dart2yaml;
 
 /**
@@ skipping 34 matching lines @@
     } else {
       yaml.write(_processElement(documentData[key]));
     }
   });
 }
 
 /**
  * Returns an escaped String form of the inputted element.
  */
 String _processElement(var element) {
-  return "\"${element.toString().replaceAll('\\', '\\\\')
-    .replaceAll("\"", "\\\"")}\"\n";
+  var contents = element.toString()
+      .replaceAll('\\', r'\\')
+      .replaceAll('"', r'\"')
+      .replaceAll('\n', r'\n');
+  return '"$contents"\n';
 }
 
 /**
  * Based on the depth in the file, this function returns the correct spacing
  * for an element in the YAML output.
  */
 void _calcSpaces(int spaceLevel, StringBuffer yaml) {
   for (int i = 0; i < spaceLevel; i++) {
     yaml.write("  ");
   }
 }