Fix memory leak caused by field type in descriptor array.

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 61 matching lines @@
 
 std::ostream& operator<<(std::ostream& os, const Descriptor& d);
 
 
 class DataDescriptor FINAL : public Descriptor {
  public:
   DataDescriptor(Handle<Name> key, int field_index,
                  PropertyAttributes attributes, Representation representation)
       : Descriptor(key, HeapType::Any(key->GetIsolate()), attributes, DATA,
                    representation, field_index) {}
-  DataDescriptor(Handle<Name> key, int field_index, Handle<HeapType> field_type,
+  // The field type is either a simple type or a map wrapped in a weak cell.
+  DataDescriptor(Handle<Name> key, int field_index,
+                 Handle<Object> wrapped_field_type,
                  PropertyAttributes attributes, Representation representation)
-      : Descriptor(key, field_type, attributes, DATA, representation,
-                   field_index) {}
+      : Descriptor(key, wrapped_field_type, attributes, DATA, representation,
+                   field_index) {
+    DCHECK(wrapped_field_type->IsSmi() || wrapped_field_type->IsWeakCell());
+  }
 };
 
 
 class DataConstantDescriptor FINAL : public Descriptor {
  public:
   DataConstantDescriptor(Handle<Name> key, Handle<Object> value,
                          PropertyAttributes attributes)
       : Descriptor(key, value, attributes, DATA_CONSTANT,
                    value->OptimalRepresentation()) {}
 };
 
 
 class AccessorConstantDescriptor FINAL : public Descriptor {
  public:
   AccessorConstantDescriptor(Handle<Name> key, Handle<Object> foreign,
                              PropertyAttributes attributes)
       : Descriptor(key, foreign, attributes, ACCESSOR_CONSTANT,
                    Representation::Tagged()) {}
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_PROPERTY_H_