Fix assertion failure because of incorrect use of MaybeObjects.

src/objects.cc

 // Copyright 2010 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 7261 matching lines @@
       break;
     }
     case PIXEL_ELEMENTS:
     case EXTERNAL_BYTE_ELEMENTS:
     case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
     case EXTERNAL_SHORT_ELEMENTS:
     case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
     case EXTERNAL_INT_ELEMENTS:
     case EXTERNAL_UNSIGNED_INT_ELEMENTS:
     case EXTERNAL_FLOAT_ELEMENTS: {
-      MaybeObject* value = GetExternalElement(index);
-      if (!value->ToObjectUnchecked()->IsUndefined()) return value;
+      MaybeObject* maybe_value = GetExternalElement(index);
+      Object* value;
+      if (!maybe_value->ToObject(&value)) return maybe_value;
+      if (!value->IsUndefined()) return value;
       break;
     }
     case DICTIONARY_ELEMENTS: {
       NumberDictionary* dictionary = element_dictionary();
       int entry = dictionary->FindEntry(index);
       if (entry != NumberDictionary::kNotFound) {
         Object* element = dictionary->ValueAt(entry);
         PropertyDetails details = dictionary->DetailsAt(entry);
         if (details.type() == CALLBACKS) {
           return GetElementWithCallback(receiver,
@@ skipping 75 matching lines @@
       break;
     }
     case PIXEL_ELEMENTS:
     case EXTERNAL_BYTE_ELEMENTS:
     case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
     case EXTERNAL_SHORT_ELEMENTS:
     case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
     case EXTERNAL_INT_ELEMENTS:
     case EXTERNAL_UNSIGNED_INT_ELEMENTS:
     case EXTERNAL_FLOAT_ELEMENTS: {
-      MaybeObject* value = GetExternalElement(index);
-      if (!value->ToObjectUnchecked()->IsUndefined()) return value;
+      MaybeObject* maybe_value = GetExternalElement(index);
+      Object* value;
+      if (!maybe_value->ToObject(&value)) return maybe_value;
+      if (!value->IsUndefined()) return value;
       break;
     }
     case DICTIONARY_ELEMENTS: {
       NumberDictionary* dictionary = element_dictionary();
       int entry = dictionary->FindEntry(index);
       if (entry != NumberDictionary::kNotFound) {
         Object* element = dictionary->ValueAt(entry);
         PropertyDetails details = dictionary->DetailsAt(entry);
         if (details.type() == CALLBACKS) {
           return GetElementWithCallback(receiver,
@@ skipping 2621 matching lines @@
   if (break_point_objects()->IsUndefined()) return 0;
   // Single beak point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 #endif
 
 
 } }  // namespace v8::internal