pkg/docgen: add --indent-json option

pkg/docgen/test/generate_json_test.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 docgen.generate_json_test;
 
 import 'dart:io';
 
 import 'package:path/path.dart' as p;
 import 'package:scheduled_test/descriptor.dart' as d;
@@ skipping 12 matching lines @@
     schedule(() {
       var codeDir = getMultiLibraryCodePath();
       expect(FileSystemEntity.isDirectorySync(codeDir), isTrue);
       return dg.docgen([codeDir], out: p.join(d.defaultRoot, 'docs'));
     });
 
     d.dir('docs', [
         d.matcherFile('index.json', isJsonMap),
         d.matcherFile('index.txt', hasSortedLines),
         d.matcherFile('library_list.json', isJsonMap),
+        d.matcherFile('library_list.json',
+            startsWith(_LIBRARY_LIST_UNINDENT_START)),

[kevmoo, 2014/04/14 21:37:49]

Checking that the default is to still generate a "flat" JSON output

         d.matcherFile('test_lib-bar.C.json', isJsonMap),
         d.matcherFile('test_lib-bar.json', isJsonMap),
         d.matcherFile('test_lib-foo.B.json', isJsonMap),
         d.matcherFile('test_lib-foo.json', isJsonMap),
         d.matcherFile('test_lib.A.json', isJsonMap),
         d.matcherFile('test_lib.B.json', isJsonMap),
         d.matcherFile('test_lib.C.json', isJsonMap),
         d.matcherFile('test_lib.json', isJsonMap),
     ]).validate();
-
   });
 }
+
+const _LIBRARY_LIST_UNINDENT_START = '{"libraries":[{"packageName":""';