NewError no longer returns a MaybeObject.

src/json-stringifier.h

 // Copyright 2012 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_STRINGIFIER_H_
 #define V8_JSON_STRINGIFIER_H_
 
 #include "src/v8.h"
 
 #include "src/conversions.h"
@@ skipping 254 matching lines @@
     return EXCEPTION;
   }
 
   int length = Smi::cast(stack_->length())->value();
   {
     DisallowHeapAllocation no_allocation;
     FixedArray* elements = FixedArray::cast(stack_->elements());
     for (int i = 0; i < length; i++) {
       if (elements->get(i) == *object) {
         AllowHeapAllocation allow_to_return_error;
-        Handle<Object> error;
-        MaybeHandle<Object> maybe_error = factory()->NewTypeError(
+        Handle<Object> error = factory()->NewTypeError(
             "circular_structure", HandleVector<Object>(NULL, 0));
-        if (maybe_error.ToHandle(&error)) isolate_->Throw(*error);
+        isolate_->Throw(*error);
         return EXCEPTION;
       }
     }
   }
   JSArray::EnsureSize(stack_, length + 1);
   FixedArray::cast(stack_->elements())->set(length, *object);
   stack_->set_length(Smi::FromInt(length + 1));
   return SUCCESS;
 }
 
@@ skipping 388 matching lines @@
       SerializeString_<uint8_t, uc16>(object);
     } else {
       SerializeString_<uc16, uc16>(object);
     }
   }
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSON_STRINGIFIER_H_