Fix json message in debugger wire protocol

runtime/bin/dbg_message.cc

 // Copyright (c) 2012, 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.
 
 #include "bin/dbg_connection.h"
 #include "bin/dbg_message.h"
 #include "bin/dartutils.h"
 #include "bin/thread.h"
 #include "bin/utils.h"
 
@@ skipping 241 matching lines @@
       FormatEncodedString(buf, location.script_url);
       buf->Printf(",\"libraryId\":%d,", location.library_id);
       buf->Printf("\"tokenOffset\":%d}", location.token_pos);
     }
     print_text_field = false;
   } else {
     buf->Printf("\"kind\":\"object\"");
     intptr_t class_id = 0;
     Dart_Handle res = Dart_GetObjClassId(object, &class_id);
     if (!Dart_IsError(res)) {
-      buf->Printf(",\"classId\":%" Pd ",", class_id);
+      buf->Printf(",\"classId\":%" Pd "", class_id);
     }
   }
   if (print_text_field) {
     buf->Printf(",\"text\":\"");
     const intptr_t max_chars = 250;
     FormatTextualValue(buf, object, max_chars, true);
     buf->Printf("\"");
   }
 }
 
@@ skipping 1051 matching lines @@
     } else {
       ASSERT(kind == kShutdown);
       RemoveIsolateMsgQueue(isolate_id);
     }
   }
   Dart_ExitScope();
 }
 
 }  // namespace bin
 }  // namespace dart