Consistently order receiver and holder argument in ElementAccessor.

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 24 matching lines @@
 
 // Abstract base class for handles that can operate on objects with differing
 // ElementsKinds.
 class ElementsAccessor {
  public:
   explicit ElementsAccessor(const char* name) : name_(name) { }
   virtual ~ElementsAccessor() { }
 
   virtual const char* name() const { return name_; }
 
-  virtual MaybeObject* Get(FixedArrayBase* backing_store,
+  // Returns true if a holder contains an element with the specified key
+  // without iterating up the prototype chain.  The caller can optionally pass
+  // in the backing store to use for the check, which must be compatible with
+  // the ElementsKind of the ElementsAccessor. If backing_store is NULL, the
+  // holder->elements() is used as the backing store.
+  virtual bool HasElement(Object* receiver,
+                          JSObject* holder,
+                          uint32_t key,
+                          FixedArrayBase* backing_store = NULL) = 0;
+
+  // Returns the element with the specified key or undefined if there is no such
+  // element. This method doesn't iterate up the prototype chain.  The caller
+  // can optionally pass in the backing store to use for the check, which must
+  // be compatible with the ElementsKind of the ElementsAccessor. If
+  // backing_store is NULL, the holder->elements() is used as the backing store.
+  virtual MaybeObject* Get(Object* receiver,
+                           JSObject* holder,
                            uint32_t key,
-                           JSObject* holder,
-                           Object* receiver) = 0;
+                           FixedArrayBase* backing_store = NULL) = 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.
-  virtual MaybeObject* SetLength(JSObject* holder,
+  virtual MaybeObject* SetLength(JSArray* holder,
                                  Object* new_length) = 0;
 
   // Modifies both the length and capacity of a JSArray, resizing the underlying
   // backing store as necessary. This method does NOT honor the semantics of
   // EcmaScript 5.1 15.4.5.2, arrays can be shrunk beyond non-deletable
   // elements. This method should only be called for array expansion OR by
   // runtime JavaScript code that use InternalArrays and don't care about
   // EcmaScript 5.1 semantics.
   virtual MaybeObject* SetCapacityAndLength(JSArray* array,
                                             int capacity,
                                             int length) = 0;
 
+  // Deletes an element in an object, returning a new elements backing store.
   virtual MaybeObject* Delete(JSObject* holder,
                               uint32_t key,
                               JSReceiver::DeleteMode mode) = 0;
 
-  virtual bool HasElement(FixedArrayBase* backing_store,
-                          uint32_t key,
-                          JSObject* holder,
-                          Object* receiver) = 0;
-
-  virtual MaybeObject* AddElementsToFixedArray(FixedArrayBase* from,
+  virtual MaybeObject* AddElementsToFixedArray(Object* receiver,
+                                               JSObject* holder,
                                                FixedArray* to,
-                                               JSObject* holder,
-                                               Object* receiver) = 0;
+                                               FixedArrayBase* from = NULL) = 0;
 
   // Returns a shared ElementsAccessor for the specified ElementsKind.
   static ElementsAccessor* ForKind(ElementsKind elements_kind) {
     ASSERT(elements_kind < kElementsKindCount);
     return elements_accessors_[elements_kind];
   }
 
   static ElementsAccessor* ForArray(FixedArrayBase* array);
 
   static void InitializeOncePerProcess();
@@ skipping 17 matching lines @@
  private:
   static ElementsAccessor** elements_accessors_;
   const char* name_;
 
   DISALLOW_COPY_AND_ASSIGN(ElementsAccessor);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ELEMENTS_H_