Issue 2399 part 2: In debugger allow modifying local variable values

src/frames.h

 // Copyright 2012 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 482 matching lines @@
   inline Object* receiver() const;
   inline void set_receiver(Object* value);
 
   // Access the parameters.
   inline Address GetParameterSlot(int index) const;
   inline Object* GetParameter(int index) const;
   inline int ComputeParametersCount() const {
     return GetNumberOfIncomingArguments();
   }
 
+  // Debugger access.
+  void SetParameterValue(int index, Object* value) const;
+
   // Check if this frame is a constructor frame invoked through 'new'.
   bool IsConstructor() const;
 
   // Check if this frame has "adapted" arguments in the sense that the
   // actual passed arguments are available in an arguments adaptor
   // frame below it on the stack.
   inline bool has_adapted_arguments() const;
   int GetArgumentsLength() const;
 
   // Garbage collection support.
@@ skipping 380 matching lines @@
 };
 
 
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap(Zone* zone);
 
 } }  // namespace v8::internal
 
 #endif  // V8_FRAMES_H_