Benchmarkify pointer swapping string encoder

include/v8.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 94 matching lines @@
 class ObjectTemplate;
 class Data;
 class AccessorInfo;
 class StackTrace;
 class StackFrame;
 
 namespace internal {
 
 class Arguments;
 class Object;
+class String;
+class ConsString;
 class Heap;
 class HeapObject;
 class Isolate;
 }
 
 
 // --- Weak Handles ---
 
 
 /**
@@ skipping 4178 matching lines @@
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_