Refactoring: move HasElementAtKey to ElementsAccessor

src/elements.h

Index: src/elements.h
diff --git a/src/elements.h b/src/elements.h
index 851c8c3d97f89d7aab4f0e910ead6c4780b18b5e..967700a51aef82aef314c6d7fe3c891b16a1ac5e 100644
--- a/src/elements.h
+++ b/src/elements.h
@@ -48,6 +48,11 @@ class ElementsAccessor {
                               uint32_t key,
                               JSReceiver::DeleteMode mode) = 0;
 
+  virtual bool HasElementAtKey(FixedArrayBase* backing_store,
+                               uint32_t key,
+                               JSObject* holder,
+                               Object* receiver) = 0;
+
   virtual MaybeObject* AddElementsToFixedArray(FixedArrayBase* from,
                                                FixedArray* to,
                                                JSObject* holder,
@@ -73,14 +78,14 @@ class ElementsAccessor {
                                  JSObject* holder,
                                  Object* receiver) = 0;
 
-  // Element handlers distinguish between indexes and keys when the manipulate
+  // Element handlers distinguish between indexes and keys when they manipulate
   // elements.  Indexes refer to elements in terms of their location in the
-  // underlying storage's backing store representation, and are between 0
+  // underlying storage's backing store representation, and are between 0 and
   // GetCapacity.  Keys refer to elements in terms of the value that would be
-  // specific 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.
+  // 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;