Reverting sharing of descriptor arrays:

src/transitions-inl.h

Index: src/transitions-inl.h
diff --git a/src/transitions-inl.h b/src/transitions-inl.h
index 5030616e4ea4ecc21bcf1092f80c753e0f849eb8..f2f0c3b7491cf86fc9d139bf030c10f4b233aae8 100644
--- a/src/transitions-inl.h
+++ b/src/transitions-inl.h
@@ -83,26 +83,22 @@ void TransitionArray::set_elements_transition(Map* transition_map,
 
 
 DescriptorArray* TransitionArray::descriptors() {
-  return DescriptorArray::cast(descriptors_pointer()->value());
+  return DescriptorArray::cast(get(kDescriptorsIndex));
 }
 
 
-void TransitionArray::set_descriptors(DescriptorArray* descriptors) {
-  ASSERT(!this->descriptors()->IsDescriptorArray() ||
-         descriptors->number_of_descriptors() == 0 ||
-         descriptors->HasEnumCache() ||
-         !this->descriptors()->HasEnumCache());
-  descriptors_pointer()->set_value(descriptors);
-}
-
-
-JSGlobalPropertyCell* TransitionArray::descriptors_pointer() {
-  return JSGlobalPropertyCell::cast(get(kDescriptorsPointerIndex));
+void TransitionArray::set_descriptors(DescriptorArray* descriptors,
+                                      WriteBarrierMode mode) {
+  Heap* heap = GetHeap();
+  WRITE_FIELD(this, kDescriptorsOffset, descriptors);
+  CONDITIONAL_WRITE_BARRIER(
+      heap, this, kDescriptorsOffset, descriptors, mode);
 }
 
 
-void TransitionArray::set_descriptors_pointer(JSGlobalPropertyCell* pointer) {
-  set(kDescriptorsPointerIndex, pointer);
+Object** TransitionArray::GetDescriptorsSlot() {
+  return HeapObject::RawField(reinterpret_cast<HeapObject*>(this),
+                              kDescriptorsOffset);
 }
 
 
@@ -196,7 +192,7 @@ PropertyDetails TransitionArray::GetTargetDetails(int transition_number) {
 
 
 int TransitionArray::Search(String* name) {
-  return internal::Search<ALL_ENTRIES>(this, name);
+  return internal::Search(this, name);
 }