Verify integrity of JSOM messages sent to debugger client

runtime/platform/json.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 PLATFORM_JSON_H_
 #define PLATFORM_JSON_H_
 
 #include "vm/allocation.h"
 #include "vm/globals.h"
 
@@ skipping 84 matching lines @@
   bool IsTrue() const {
     return scanner_.CurrentToken() == JSONScanner::TokenTrue;
   }
   bool IsFalse() const {
     return scanner_.CurrentToken() == JSONScanner::TokenFalse;
   }
   bool IsNull() const {
     return scanner_.CurrentToken() == JSONScanner::TokenNull;
   }
 
+  // Debugging method to check for validity of a JSON message.
+  bool CheckMessage();
+
  private:
+  void CheckObject();
+  void CheckArray();
+  void CheckValue();
+
   JSONScanner scanner_;
   const char* json_object_;
   bool error_;
 };
 
 
 // TextBuffer maintains a dynamic character buffer with a printf-style way to
 // append text.
 class TextBuffer : ValueObject {
  public:
@@ skipping 13 matching lines @@
  private:
   void EnsureCapacity(intptr_t len);
   char* buf_;
   intptr_t buf_size_;
   intptr_t msg_len_;
 };
 
 }  // namespace dart
 
 #endif  // PLATFORM_JSON_H_