Automatically determine ElementsKind name for debug printing

src/elements.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 19 matching lines @@
 
 #include "objects.h"
 
 namespace v8 {
 namespace internal {
 
 // Abstract base class for handles that can operate on objects with differing
 // ElementsKinds.
 class ElementsAccessor {
  public:
-  ElementsAccessor() { }
+  explicit ElementsAccessor(const char* name) : name_(name) { }
   virtual ~ElementsAccessor() { }
+
+  virtual const char* name() const { return name_; }
+
   virtual MaybeObject* Get(FixedArrayBase* backing_store,
                            uint32_t key,
                            JSObject* holder,
                            Object* receiver) = 0;
 
   // Modifies the length data property as specified for JSArrays and resizes the
   // underlying backing store accordingly. The method honors the semantics of
   // changing array sizes as defined in EcmaScript 5.1 15.4.5.2, i.e. array that
   // have non-deletable elements can only be shrunk to the size of highest
   // element that is non-deletable.
@@ skipping 45 matching lines @@
   // GetCapacity.  Keys refer to elements in terms of the value that would be
   // specified in JavaScript to access the element. In most implementations,
   // keys are equivalent to indexes, and GetKeyForIndex returns the same value
   // it is passed. In the NumberDictionary ElementsAccessor, GetKeyForIndex maps
   // the index to a key using the KeyAt method on the NumberDictionary.
   virtual uint32_t GetKeyForIndex(FixedArrayBase* backing_store,
                                   uint32_t index) = 0;
 
  private:
   static ElementsAccessor** elements_accessors_;
+  const char* name_;
 
   DISALLOW_COPY_AND_ASSIGN(ElementsAccessor);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ELEMENTS_H_