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 25 matching lines @@
 #include "spaces-inl.h"
 #include "token.h"
 
 namespace v8 {
 namespace internal {
 
 // A simple json parser.
 template <bool seq_ascii>
 class JsonParser BASE_EMBEDDED {
  public:
-  static MaybeHandle<Object> Parse(Handle<String> source) {
+  MUST_USE_RESULT static MaybeHandle<Object> Parse(Handle<String> source) {
     return JsonParser(source).ParseJson();
   }
 
   static const int kEndOfString = -1;
 
  private:
   explicit JsonParser(Handle<String> source)
       : source_(source),
         source_length_(source->length()),
         isolate_(source->map()->GetHeap()->isolate()),
@@ skipping 378 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_