Remove SealHandleScope from TryNumberToSize conversion

src/conversions-inl.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_CONVERSIONS_INL_H_
 #define V8_CONVERSIONS_INL_H_
 
 #include <float.h>         // Required for DBL_MAX and on Win32 for finite()
 #include <limits.h>        // Required for INT_MAX etc.
 #include <stdarg.h>
@@ skipping 115 matching lines @@
   if (number->IsSmi()) return Smi::cast(number)->value();
   return DoubleToUint32(number->Number());
 }
 
 int64_t NumberToInt64(Object* number) {
   if (number->IsSmi()) return Smi::cast(number)->value();
   return static_cast<int64_t>(number->Number());
 }
 
 bool TryNumberToSize(Isolate* isolate, Object* number, size_t* result) {
-  SealHandleScope shs(isolate);
+  // Do not create handles in this function! Don't use SealHandleScope because
+  // the function can be used concurrently.
   if (number->IsSmi()) {
     int value = Smi::cast(number)->value();
     DCHECK(static_cast<unsigned>(Smi::kMaxValue) <=
            std::numeric_limits<size_t>::max());
     if (value >= 0) {
       *result = static_cast<size_t>(value);
       return true;
     }
     return false;
   } else {
@@ skipping 611 matching lines @@
   buffer[buffer_pos] = '\0';
 
   double converted = Strtod(Vector<const char>(buffer, buffer_pos), exponent);
   return (sign == NEGATIVE) ? -converted : converted;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CONVERSIONS_INL_H_