Remove one more case behind --es5_readonly flag.

src/objects.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2099 matching lines @@
         *done = result.IsReadOnly();
         break;
       case INTERCEPTOR: {
         PropertyAttributes attr =
             result.holder()->GetPropertyAttributeWithInterceptor(
                 this, name, true);
         *done = !!(attr & READ_ONLY);
         break;
       }
       case CALLBACKS: {
+        if (!FLAG_es5_readonly && result.IsReadOnly()) break;
         *done = true;
         return SetPropertyWithCallback(result.GetCallbackObject(),
             name, value, result.holder(), strict_mode);
       }
       case HANDLER: {
         return result.proxy()->SetPropertyViaPrototypesWithHandler(
             this, name, value, attributes, strict_mode, done);
       }
       case MAP_TRANSITION:
       case CONSTANT_TRANSITION:
@@ skipping 413 matching lines @@
 void JSObject::LookupRealNamedPropertyInPrototypes(String* name,
                                                    LookupResult* result) {
   Heap* heap = GetHeap();
   for (Object* pt = GetPrototype();
        pt != heap->null_value();
        pt = pt->GetPrototype()) {
     if (pt->IsJSProxy()) {
       return result->HandlerResult(JSProxy::cast(pt));
     }
     JSObject::cast(pt)->LocalLookupRealNamedProperty(name, result);
+    ASSERT(!(result->IsProperty() && result->type() == INTERCEPTOR));
     if (result->IsProperty()) return;
   }
   result->NotFound();
 }
 
 
 // We only need to deal with CALLBACKS and INTERCEPTORS
 MaybeObject* JSObject::SetPropertyWithFailedAccessCheck(
     LookupResult* result,
     String* name,
@@ skipping 10670 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal