Remove the holder_ field from LookupResult

src/property.h

 // Copyright 2014 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_PROPERTY_H_
 #define V8_PROPERTY_H_
 
 #include <iosfwd>
 
 #include "src/factory.h"
@@ skipping 92 matching lines @@
                    Representation::Tagged()) {}
 };
 
 
 class LookupResult FINAL BASE_EMBEDDED {
  public:
   explicit LookupResult(Isolate* isolate)
       : isolate_(isolate),
         next_(isolate->top_lookup_result()),
         lookup_type_(NOT_FOUND),
-        holder_(NULL),
         transition_(NULL),
         details_(NONE, DATA, Representation::None()) {
     isolate->set_top_lookup_result(this);
   }
 
   ~LookupResult() {
     DCHECK(isolate()->top_lookup_result() == this);
     isolate()->set_top_lookup_result(next_);
   }
 
   Isolate* isolate() const { return isolate_; }
 
-  void DescriptorResult(JSObject* holder, PropertyDetails details, int number) {
+  void DescriptorResult(PropertyDetails details, int number) {
     lookup_type_ = DESCRIPTOR_TYPE;
-    holder_ = holder;
     transition_ = NULL;
     details_ = details;
     number_ = number;
   }
 
-  void TransitionResult(JSObject* holder, Map* target) {
+  void TransitionResult(Map* target) {
     lookup_type_ = TRANSITION_TYPE;
     number_ = target->LastAdded();
     details_ = target->instance_descriptors()->GetDetails(number_);
-    holder_ = holder;
     transition_ = target;
   }
 
   void NotFound() {
     lookup_type_ = NOT_FOUND;
     details_ = PropertyDetails(NONE, DATA, 0);
-    holder_ = NULL;
     transition_ = NULL;
   }
 
   Representation representation() const {
     DCHECK(IsFound());
     return details_.representation();
   }
 
   // Property callbacks does not include transitions to callbacks.
   bool IsAccessorConstant() const {
@@ skipping 69 matching lines @@
 
   void Iterate(ObjectVisitor* visitor);
 
  private:
   Isolate* isolate_;
   LookupResult* next_;
 
   // Where did we find the result;
   enum { NOT_FOUND, DESCRIPTOR_TYPE, TRANSITION_TYPE } lookup_type_;
 
-  JSReceiver* holder_;
   Map* transition_;
   int number_;
   PropertyDetails details_;
 };
 
 
 std::ostream& operator<<(std::ostream& os, const LookupResult& r);
 } }  // namespace v8::internal
 
 #endif  // V8_PROPERTY_H_