fix(playback_middleware): use dart:convert (v0.8.7)

Author: chirayuk

playback_middleware/lib/playback.js

@@ -13,7 +13,7 @@ function playback(opts) {
     var lines = [
         'library angular.core.service.playback_data;',
         '',
-        'import "dart:json" as json;',
+        'import "dart:convert";',
         '',
         '// Auto-generated by record-playback',
         '',
@@ -23,7 +23,7 @@ function playback(opts) {
     records.forEach(function(r) {
       var keyString = JSON.stringify(r.key).replace(/\$/g, '\\$');
       var valueString = JSON.stringify(r.data).replace(/\$/g, '\\$');
-      lines.push('  ' + keyString + ': json.parse(' + valueString + '),');
+      lines.push('  ' + keyString + ': JSON.decode(' + valueString + '),');
     });
 
     lines.push('};');