ExtendStorageStub added, it is aimed for extending objects backing store when it runs out of space.

src/hydrogen.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_HYDROGEN_H_
 #define V8_HYDROGEN_H_
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 1786 matching lines @@
                                      HValue* capacity);
   HAllocate* AllocateJSArrayObject(AllocationSiteMode mode);
   HConstant* EstablishElementsAllocationSize(ElementsKind kind, int capacity);
 
   HAllocate* BuildAllocateElements(ElementsKind kind, HValue* size_in_bytes);
 
   void BuildInitializeElementsHeader(HValue* elements,
                                      ElementsKind kind,
                                      HValue* capacity);
 
-  HValue* BuildAllocateElementsAndInitializeElementsHeader(ElementsKind kind,
-                                                           HValue* capacity);
+  // Build allocation and header initialization code for respective successor
+  // of FixedArrayBase.
+  HValue* BuildAllocateAndInitializeArray(ElementsKind kind, HValue* capacity);
 
   // |array| must have been allocated with enough room for
   // 1) the JSArray and 2) an AllocationMemento if mode requires it.
   // If the |elements| value provided is NULL then the array elements storage
   // is initialized with empty array.
   void BuildJSArrayHeader(HValue* array,
                           HValue* array_map,
                           HValue* elements,
                           AllocationSiteMode mode,
                           ElementsKind elements_kind,
@@ skipping 11 matching lines @@
                                   ElementsKind elements_kind,
                                   HValue* from,
                                   HValue* to,
                                   HValue* value);
 
   void BuildFillElementsWithHole(HValue* elements,
                                  ElementsKind elements_kind,
                                  HValue* from,
                                  HValue* to);
 
+  void BuildCopyProperties(HValue* from_properties, HValue* to_properties,
+                           HValue* length, HValue* capacity);
+
   void BuildCopyElements(HValue* from_elements,
                          ElementsKind from_elements_kind,
                          HValue* to_elements,
                          ElementsKind to_elements_kind,
                          HValue* length,
                          HValue* capacity);
 
   HValue* BuildCloneShallowArrayCow(HValue* boilerplate,
                                     HValue* allocation_site,
                                     AllocationSiteMode mode,
@@ skipping 1055 matching lines @@
   }
 
  private:
   HGraphBuilder* builder_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_