pkg/docgen: add --indent-json option

pkg/docgen/test/generate_json_test.dart

Index: pkg/docgen/test/generate_json_test.dart
diff --git a/pkg/docgen/test/generate_json_test.dart b/pkg/docgen/test/generate_json_test.dart
index 9149a96316ae6b71b137a65da4fe10221b36af52..a6ac53d3ea98479e3939c67a48c1689e81f83065 100644
--- a/pkg/docgen/test/generate_json_test.dart
+++ b/pkg/docgen/test/generate_json_test.dart
@@ -30,6 +30,8 @@ void main() {
         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),
@@ -39,6 +41,7 @@ void main() {
         d.matcherFile('test_lib.C.json', isJsonMap),
         d.matcherFile('test_lib.json', isJsonMap),
     ]).validate();
-
   });
 }
+
+const _LIBRARY_LIST_UNINDENT_START = '{"libraries":[{"packageName":""';