To diagnose chromium bug 284577, some additional CHECKS. TODOs are

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 437d29b82e75a900410352d1e5261c4f6b7791be..8f1f411eec5914e366ebb13e8d277bba8c1e491e 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -1824,7 +1824,8 @@ void HGraphBuilder::BuildCompareNil(
 HValue* HGraphBuilder::BuildCreateAllocationMemento(HValue* previous_object,
                                                     int previous_object_size,
                                                     HValue* alloc_site) {
-  ASSERT(alloc_site != NULL);
+  // TODO(mvstanton): ASSERT altered to CHECK to diagnose chromium bug 284577
+  CHECK(alloc_site != NULL);
   HInnerAllocatedObject* alloc_memento = Add<HInnerAllocatedObject>(
       previous_object, previous_object_size);
   Handle<Map> alloc_memento_map(
@@ -1832,6 +1833,12 @@ HValue* HGraphBuilder::BuildCreateAllocationMemento(HValue* previous_object,
   AddStoreMapConstant(alloc_memento, alloc_memento_map);
   HObjectAccess access = HObjectAccess::ForAllocationMementoSite();
   Add<HStoreNamedField>(alloc_memento, access, alloc_site);
+  // TODO(mvstanton): to diagnose chromium bug 284577 we could/should
+  // dereference the alloc_site here. We could do a map check. However it has
+  // a performance impact so I'm not doing that right away.
+  // for example, something like:
+  // Add<HLoadNamedField>(alloc_site,
+  //                      HObjectAccess::ForAllocationSiteTransitionInfo());

[Hannes Payer (out of office), 2013/09/11 13:25:35]

I guess you are planing to land this in a different CL, remove this code here.

   return alloc_memento;
 }