Return MaybeHandle from SetElement and DeleteElement.

src/scopes.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1096 matching lines @@
       }
 #endif
 
       // Inconsistent use of module. Throw a syntax error.
       // TODO(rossberg): generate more helpful error message.
       MessageLocation location(
           info->script(), proxy->position(), proxy->position());
       Isolate* isolate = info->isolate();
       Factory* factory = isolate->factory();
       Handle<JSArray> array = factory->NewJSArray(1);
-      USE(JSObject::SetElement(array, 0, var->name(), NONE, STRICT));
+      JSObject::SetElement(array, 0, var->name(), NONE, STRICT).Assert();
       Handle<Object> result =
           factory->NewSyntaxError("module_type_error", array);
       isolate->Throw(*result, &location);
       return false;
     }
   }
 
   proxy->BindTo(var);
 
   return true;
@@ skipping 267 matching lines @@
 }
 
 
 int Scope::ContextLocalCount() const {
   if (num_heap_slots() == 0) return 0;
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS -
       (function_ != NULL && function_->proxy()->var()->IsContextSlot() ? 1 : 0);
 }
 
 } }  // namespace v8::internal