Fix indentation of parser trace (several threads may compile at once).

runtime/vm/parser.h

 // 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.
 
 #ifndef VM_PARSER_H_
 #define VM_PARSER_H_
 
 #include "include/dart_api.h"
 
 #include "platform/assert.h"
@@ skipping 821 matching lines @@
 
   // Each try in this function gets its own try index.
   int16_t AllocateTryIndex();
 
   int16_t last_used_try_index_;
 
   bool unregister_pending_function_;
 
   LocalScope* async_temp_scope_;
 
+  // Indentation of parser trace.
+  intptr_t trace_indent_;
+
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };
 
 }  // namespace dart
 
 #endif  // VM_PARSER_H_