Return MaybeHandle from Object::ToSmi.

src/objects-inl.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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 1019 matching lines @@
     ? static_cast<double>(reinterpret_cast<Smi*>(this)->value())
     : reinterpret_cast<HeapNumber*>(this)->value();
 }
 
 
 bool Object::IsNaN() {
   return this->IsHeapNumber() && std::isnan(HeapNumber::cast(this)->value());
 }
 
 
-Handle<Object> Object::ToSmi(Isolate* isolate, Handle<Object> object) {
-  if (object->IsSmi()) return object;
+MaybeHandle<Smi> Object::ToSmi(Isolate* isolate, Handle<Object> object) {
+  if (object->IsSmi()) return Handle<Smi>::cast(object);
   if (object->IsHeapNumber()) {
     double value = Handle<HeapNumber>::cast(object)->value();
     int int_value = FastD2I(value);
     if (value == FastI2D(int_value) && Smi::IsValid(int_value)) {
       return handle(Smi::FromInt(int_value), isolate);
     }
   }
-  return Handle<Object>();
+  return Handle<Smi>();
 }
 
 
 MaybeHandle<JSReceiver> Object::ToObject(Isolate* isolate,
                                          Handle<Object> object) {
   return ToObject(
       isolate, object, handle(isolate->context()->native_context(), isolate));
 }
 
 
@@ skipping 5922 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_