This is a little experiment to move Failure to a superclass above Object...

src/objects-inl.h

Index: src/objects-inl.h
===================================================================
--- src/objects-inl.h	(revision 5559)
+++ src/objects-inl.h	(working copy)
@@ -1204,9 +1204,11 @@
 }
 
 
+  Object* obj;
+  { TryAllocation t = map()->GetFastElementsMap();
+    if (!t->ToObject(&obj)) return t;
+  }
 Object* JSObject::ResetElements() {
-  Object* obj = map()->GetFastElementsMap();
-  if (obj->IsFailure()) return obj;
   set_map(Map::cast(obj));
   initialize_elements();
   return this;
@@ -2482,9 +2484,11 @@
 
 
 Object* Map::GetFastElementsMap() {
+  Object* obj;
+  { TryAllocation t = CopyDropTransitions();
+    if (!t->ToObject(&obj)) return t;
+  }
   if (has_fast_elements()) return this;
-  Object* obj = CopyDropTransitions();
-  if (obj->IsFailure()) return obj;
   Map* new_map = Map::cast(obj);
   new_map->set_has_fast_elements(true);
   Counters::map_slow_to_fast_elements.Increment();
@@ -2493,9 +2497,11 @@
 
 
 Object* Map::GetSlowElementsMap() {
+  Object* obj;
+  { TryAllocation t = CopyDropTransitions();
+    if (!t->ToObject(&obj)) return t;
+  }
   if (!has_fast_elements()) return this;
-  Object* obj = CopyDropTransitions();
-  if (obj->IsFailure()) return obj;
   Map* new_map = Map::cast(obj);
   new_map->set_has_fast_elements(false);
   Counters::map_fast_to_slow_elements.Increment();
@@ -3199,9 +3205,11 @@
   ASSERT(HasFastElements());
   FixedArray* elems = FixedArray::cast(elements());
   if (elems->map() != Heap::fixed_cow_array_map()) return elems;
-  Object* writable_elems = Heap::CopyFixedArrayWithMap(elems,
-                                                       Heap::fixed_array_map());
-  if (writable_elems->IsFailure()) return writable_elems;
+  Object* writable_elems;
+  { TryAllocation t = Heap::CopyFixedArrayWithMap(elems,
+                                                         Heap::fixed_array_map());
+    if (!t->ToObject(&writable_elems)) return t;
+  }
   set_elements(FixedArray::cast(writable_elems));
   Counters::cow_arrays_converted.Increment();
   return writable_elems;