Cleanup adding elements and in particular dictionary elements

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 1997 matching lines @@
       Handle<JSObject> object,
       Arguments* arguments,
       uint32_t first_arg,
       uint32_t arg_count,
       EnsureElementsMode mode);
 
   // Would we convert a fast elements array to dictionary mode given
   // an access at key?
   bool WouldConvertToSlowElements(uint32_t index);
   inline bool WouldConvertToSlowElements(Handle<Object> key);
-  // Do we want to keep the elements in fast case when increasing the
-  // capacity?
-  bool ShouldConvertToSlowElements(int new_capacity);
-  // Returns true if the backing storage for the slow-case elements of
-  // this object takes up nearly as much space as a fast-case backing
-  // storage would.  In that case the JSObject should have fast
-  // elements.
-  bool ShouldConvertToFastElements();
+  // Do we want to keep fast elements when adding an element at |index|?
+  // Returns |new_capacity| indicating to which capacity the object should be
+  // increased.
+  bool ShouldConvertToSlowElements(uint32_t capacity, uint32_t index,
+                                   uint32_t* new_capacity);
   ElementsKind BestFittingFastElementsKind();
 
   // Computes the new capacity when expanding the elements of a JSObject.
   static uint32_t NewElementsCapacity(uint32_t old_capacity) {
     // (old_capacity + 50%) + 16
     return old_capacity + (old_capacity >> 1) + 16;
   }
 
   // These methods do not perform access checks!
   static void UpdateAllocationSite(Handle<JSObject> object,
@@ skipping 8097 matching lines @@
 //    - slow, backing storage is a HashTable with numbers as keys.
 class JSArray: public JSObject {
  public:
   // [length]: The length property.
   DECL_ACCESSORS(length, Object)
 
   // Overload the length setter to skip write barrier when the length
   // is set to a smi. This matches the set function on FixedArray.
   inline void set_length(Smi* length);
 
-  static void JSArrayUpdateLengthFromIndex(Handle<JSArray> array,
-                                           uint32_t index,
-                                           Handle<Object> value);
-
   static bool HasReadOnlyLength(Handle<JSArray> array);
   static bool WouldChangeReadOnlyLength(Handle<JSArray> array, uint32_t index);
   static MaybeHandle<Object> ReadOnlyLengthError(Handle<JSArray> array);
 
   // Initialize the array with the given capacity. The function may
   // fail due to out-of-memory situations, but only if the requested
   // capacity is non-zero.
   static void Initialize(Handle<JSArray> array, int capacity, int length = 0);
 
   // If the JSArray has fast elements, and new_length would result in
@@ skipping 665 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_