Remove usage of dart:json.

samples/third_party/dromaeo/tests/dom-modify-html.dart

Index: samples/third_party/dromaeo/tests/dom-modify-html.dart
diff --git a/samples/third_party/dromaeo/tests/dom-modify-html.dart b/samples/third_party/dromaeo/tests/dom-modify-html.dart
index 7599b060bdc4d482e9ce05562343d5009181255d..e9cb8be707188c9cbc168c4696eeb83838b2b6be 100644
--- a/samples/third_party/dromaeo/tests/dom-modify-html.dart
+++ b/samples/third_party/dromaeo/tests/dom-modify-html.dart
@@ -1,7 +1,7 @@
 library dromaeo;
 import 'dart:async';
 import 'dart:html';
-import 'dart:json' as json;
+import "dart:convert";
 import 'dart:math' as Math;
 part 'Common.dart';
 part 'RunnerSuite.dart';
@@ -11,9 +11,10 @@ void main() {
   var random = new Math.Random();
 
   String str = 'null';
-  // Very ugly way to build up the string, but let's mimic JS version as much as possible.
+  // Very ugly way to build up the string, but let's mimic JS version as much as
+  // possible.
   for (int i = 0; i < 1024; i++) {
-    str = "$str${new String.fromCharCodes([((25 * random.nextDouble()) + 97).toInt()])}";
+    str += new String.fromCharCode(((25 * random.nextDouble()) + 97).toInt());

[Emily Fortuna, 2013/08/28 21:09:54]

Are these two forms identical, perf-wise? I'm not certain what's going on "under
the hood"

[floitsch, 2013/08/28 21:12:15]

The new one could be faster (although I'm not sure we already implemented it).
If speed is an issue it shouldn't use string-concatenation, but a string-buffer.

[Emily Fortuna, 2013/08/28 21:19:01]

Agreed StringBuffer is the fastest way for sure-- I think they were trying to
keep this test similar to the original JS version so that they could compare
apples-to...almost apples. :-)

   }
 
   List<Node> elems = <Node>[];