Revert "Add "own" symbols support."

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 29af1d83373193db4face20c934c39f939a276be..aa9984000086e372087aeb1adc52613d5fcff29b 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -3560,11 +3560,6 @@ void JSObject::LookupRealNamedProperty(Handle<Name> name,
 
 void JSObject::LookupRealNamedPropertyInPrototypes(Handle<Name> name,
                                                    LookupResult* result) {
-  if (name->IsOwn()) {
-    result->NotFound();
-    return;
-  }
-
   DisallowHeapAllocation no_gc;
   Isolate* isolate = GetIsolate();
   for (PrototypeIterator iter(isolate, this); !iter.IsAtEnd(); iter.Advance()) {
@@ -6112,7 +6107,7 @@ void JSReceiver::LookupOwn(
   }
 
   js_object->LookupOwnRealNamedProperty(name, result);
-  if (result->IsFound() || name->IsOwn() || !search_hidden_prototypes) return;
+  if (result->IsFound() || !search_hidden_prototypes) return;
 
   PrototypeIterator iter(GetIsolate(), js_object);
   if (!iter.GetCurrent()->IsJSReceiver()) return;
@@ -6131,10 +6126,6 @@ void JSReceiver::Lookup(Handle<Name> name, LookupResult* result) {
        !iter.IsAtEnd(); iter.Advance()) {
     JSReceiver::cast(iter.GetCurrent())->LookupOwn(name, result, false);
     if (result->IsFound()) return;
-    if (name->IsOwn()) {
-      result->NotFound();
-      return;
-    }
   }
   result->NotFound();
 }