Return MaybeHandle from SetProperty.

src/json-parser.h

 // Copyright 2011 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 424 matching lines @@
       } else {
         key = ParseJsonInternalizedString();
         if (key.is_null() || c0_ != ':') return ReportUnexpectedCharacter();
 
         AdvanceSkipWhitespace();
         value = ParseJsonValue();
         if (value.is_null()) return ReportUnexpectedCharacter();
       }
 
       JSObject::SetLocalPropertyIgnoreAttributes(
-          json_object, key, value, NONE);
+          json_object, key, value, NONE).Assert();
     } while (MatchSkipWhiteSpace(','));
     if (c0_ != '}') {
       return ReportUnexpectedCharacter();
     }
 
     // If we transitioned until the very end, transition the map now.
     if (transitioning) {
       JSObject::AllocateStorageForMap(json_object, map);
       int length = properties.length();
       for (int i = 0; i < length; i++) {
@@ skipping 342 matching lines @@
 
   ASSERT_EQ('"', c0_);
   // Advance past the last '"'.
   AdvanceSkipWhitespace();
   return result;
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSON_PARSER_H_