Rework "analysis.updateContent" analysis server request.

pkg/analysis_server/tool/spec/to_html.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.
 
 /**
  * Code for displaying the API as HTML.  This is used both for generating a
  * full description of the API as a web page, and for generating doc comments
  * in generated code.
  */
 library to.html;
@@ skipping 468 matching lines @@
     });
   }
 
   @override
   void visitTypeObjectField(TypeObjectField typeObjectField) {
     dt('field', () {
       b(() {
         i(() {
           write(typeObjectField.name);
           if (typeObjectField.value != null) {
-            write(' = ${typeObjectField.value}');
+            write(' = ${JSON.encode(typeObjectField.value)}');
           } else {
             write(' ( ');
             if (typeObjectField.optional) {
               gray(() {
                 write('optional');
               });
               write(' ');
             }
             TypeVisitor typeVisitor = new TypeVisitor(api, short: true);
             addAll(typeVisitor.collectHtml(() {
@@ skipping 19 matching lines @@
  */
 main() {
   ToHtmlVisitor visitor = new ToHtmlVisitor(readApi());
   dom.Document document = new dom.Document();
   for (dom.Node node in visitor.collectHtml(visitor.visitApi)) {
     document.append(node);
   }
   File outputFile = new File('../../doc/api.html');
   outputFile.writeAsStringSync(document.outerHtml);
 }