Merged r16816 into trunk branch.

Reverted ("Chromium 284577 needs a mitigation CL added." (svn-id 16742)). Also changed a check in heap-inl.h for diagnosing 284577 into an assert.

R=mvstanton@chromium.org
BUG=

Review URL: https://codereview.chromium.org/24169006

git-svn-id: http://v8.googlecode.com/svn/trunk@16822 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/heap-inl.h b/src/heap-inl.h
index 86aff1a..4f19603 100644
--- a/src/heap-inl.h
+++ b/src/heap-inl.h
@@ -525,8 +525,8 @@
     return;
   }
 
-  // TODO(hpayer): temporary debugging code for issue 284577.
-  CHECK(object->map() != object->GetHeap()->allocation_memento_map());
+  // AllocationMementos are unrooted and shouldn't survive a scavenge
+  ASSERT(object->map() != object->GetHeap()->allocation_memento_map());
   // Call the slow part of scavenge object.
   return ScavengeObjectSlow(p, object);
 }