Use GetProperty for getting elements.

src/json-parser.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_JSON_PARSER_H_
 #define V8_JSON_PARSER_H_
 
 #include "src/v8.h"
 
 #include "src/char-predicates-inl.h"
@@ skipping 293 matching lines @@
 ParseElementResult JsonParser<seq_one_byte>::ParseElement(
     Handle<JSObject> json_object) {
   uint32_t index = 0;
   // Maybe an array index, try to parse it.
   if (c0_ == '0') {
     // With a leading zero, the string has to be "0" only to be an index.
     Advance();
   } else {
     do {
       int d = c0_ - '0';
-      if (index > 429496729U - ((d > 5) ? 1 : 0)) break;
+      if (index > 429496729U - ((d + 3) >> 3)) break;
       index = (index * 10) + d;
       Advance();
     } while (IsDecimalDigit(c0_));
   }
 
   if (c0_ == '"') {
     // Successfully parsed index, parse and store element.
     AdvanceSkipWhitespace();
 
     if (c0_ == ':') {
@@ skipping 509 matching lines @@
 
   DCHECK_EQ('"', c0_);
   // Advance past the last '"'.
   AdvanceSkipWhitespace();
   return result;
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSON_PARSER_H_