Move json, uri, utf and crypto libraries into the VM.

sdk/lib/json/json_sources.gypi

Index: sdk/lib/json/json_sources.gypi
===================================================================
--- sdk/lib/json/json_sources.gypi	(revision 18800)
+++ sdk/lib/json/json_sources.gypi	(working copy)
@@ -2,9 +2,9 @@
 # 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 file contains all sources for the dart:io library.
+# This file contains all sources for the dart:json library.
 {
   'sources': [
-    '../../sdk/lib/json/json.dart',
+    'json_base.dart',
   ],
 }