Add a missing check for a failure result.

src/elements.cc

Index: src/elements.cc
===================================================================
--- src/elements.cc	(revision 10744)
+++ src/elements.cc	(working copy)
@@ -911,7 +911,9 @@
   MaybeObject* maybe_obj = array->GetHeap()->AllocateFixedArray(1);
   if (!maybe_obj->To(&new_backing_store)) return maybe_obj;
   new_backing_store->set(0, length);
-  array->SetContent(new_backing_store);
+  { MaybeObject* result = array->SetContent(new_backing_store);
+    if (result->IsFailure()) return result;
+  }
   return array;
 }