The metadata part of TypeFeedbackVector is extracted to TypeFeedbackMetadata array.

test/cctest/test-feedback-vector.h

 // Copyright 2015 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_TEST_FEEDBACK_VECTOR_H_
 #define V8_TEST_FEEDBACK_VECTOR_H_
 
 #include "src/objects.h"
 
 
 namespace v8 {
 namespace internal {
 
 // Helper class that allows to write tests in a slot size independent manner.
 // Use helper.slot(X) to get X'th slot identifier.
 class FeedbackVectorHelper {
  public:
   explicit FeedbackVectorHelper(Handle<TypeFeedbackVector> vector)
       : vector_(vector) {
-    int slot_count = vector->Slots();
+    int slot_count = vector->slot_count();
     slots_.reserve(slot_count);
-    TypeFeedbackMetadataIterator iter(vector);
+    TypeFeedbackMetadataIterator iter(vector->metadata());
     while (iter.HasNext()) {
       FeedbackVectorSlot slot = iter.Next();
       slots_.push_back(slot);
     }
   }
 
   Handle<TypeFeedbackVector> vector() { return vector_; }
 
   // Returns slot identifier by numerical index.
   FeedbackVectorSlot slot(int index) const { return slots_[index]; }
 
   // Returns the number of slots in the feedback vector.
   int slot_count() const { return static_cast<int>(slots_.size()); }
 
  private:
   Handle<TypeFeedbackVector> vector_;
   std::vector<FeedbackVectorSlot> slots_;
 };
 
+template <typename Spec>
+Handle<TypeFeedbackVector> NewTypeFeedbackVector(Isolate* isolate, Spec* spec) {
+  Handle<TypeFeedbackMetadata> metadata =
+      TypeFeedbackMetadata::New(isolate, spec);
+  return TypeFeedbackVector::New(isolate, metadata);
+}
+
+
 }  // namespace internal
 }  // namespace v8
 
 #endif