Request for comments on overall approach.

runtime/vm/freelist.cc

Index: runtime/vm/freelist.cc
diff --git a/runtime/vm/freelist.cc b/runtime/vm/freelist.cc
index 054a023c39425c902e6af1db4f7cee2ae9ecd7bf..3a0dc0a581a46cdce3ea569c3b7d6acc3ca03e60 100644
--- a/runtime/vm/freelist.cc
+++ b/runtime/vm/freelist.cc
@@ -25,33 +25,23 @@ RawClass* AllocateFakeClass() {
 }
 
 
-RawClass* FreeListElement::minimal_element_class_ = NULL;
-RawClass* FreeListElement::element_class_ = NULL;
-
+RawClass* FreeListElement::freelist_class_ = NULL;
 
 FreeListElement* FreeListElement::AsElement(uword addr, intptr_t size) {
   ASSERT(size >= kObjectAlignment);
   ASSERT(Utils::IsAligned(size, kObjectAlignment));
 
   FreeListElement* result = reinterpret_cast<FreeListElement*>(addr);
-  if (size == kObjectAlignment) {
-    result->class_ = minimal_element_class_;
-  } else {
-    result->class_ = element_class_;
-    *result->SizeAddress() = size;
-  }
   result->set_next(NULL);
-  ASSERT(result->Size() == size);
+  result->set_size(size);
   return result;
 }
 
 
 void FreeListElement::InitOnce() {
   ASSERT(sizeof(FreeListElement) == kObjectAlignment);
-  ASSERT(minimal_element_class_ == NULL);
-  ASSERT(element_class_ == NULL);
-  minimal_element_class_ = AllocateFakeClass();
-  element_class_ = AllocateFakeClass();
+  ASSERT(OFFSET_OF(FreeListElement, next_) == Object::tags_offset());
+  freelist_class_ = AllocateFakeClass();
 }
 
 
@@ -88,7 +78,7 @@ uword FreeList::TryAllocate(intptr_t size) {
   FreeListElement* previous = NULL;
   FreeListElement* current = free_lists_[kNumLists];
   while (current != NULL) {
-    if (current->Size() >= size) {
+    if (current->size() >= size) {
       // Found an element large enough to hold the requested size. Dequeue,
       // split and enqueue the remainder.
       if (previous == NULL) {
@@ -146,7 +136,7 @@ FreeListElement* FreeList::DequeueElement(intptr_t index) {
 
 void FreeList::SplitElementAfterAndEnqueue(FreeListElement* element,
                                            intptr_t size) {
-  intptr_t remainder_size = element->Size() - size;
+  intptr_t remainder_size = element->size() - size;
   if (remainder_size == 0) return;
 
   element = FreeListElement::AsElement(reinterpret_cast<uword>(element) + size,