DocumentLoader::isCommittedButEmpty is timing-dependent.

Source/core/loader/DocumentLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 276 matching lines @@
         // If this is an empty document, it will not have actually been created yet. Commit dummy data so that
         // DocumentWriter::begin() gets called and creates the Document.
         if (!m_writer)
             commitData(0, 0);
     }
 
     endWriting(m_writer.get());
 
     if (!m_mainDocumentError.isNull())
         return;
-    m_state = MainResourceDone;
+    m_state = url() == blankURL() || (m_mainResource && !m_mainResource->encodedSize()) ? MainResourceDoneButEmpty : MainResourceDone;
 
     // If the document specified an application cache manifest, it violates the author's intent if we store it in the memory cache
     // and deny the appcache the chance to intercept it in the future, so remove from the memory cache.
     if (m_frame) {
         if (m_mainResource && m_frame->document()->hasAppCacheManifest())
             memoryCache()->remove(m_mainResource.get());
     }
     m_applicationCacheHost->finishedLoadingMainResource();
     clearMainResourceHandle();
 }
@@ skipping 561 matching lines @@
 {
     m_writer = createWriterFor(ownerDocument, init, mimeType(), m_writer ? m_writer->encoding() : emptyAtom, true, ForceSynchronousParsing);
     if (!source.isNull())
         m_writer->appendReplacingData(source);
     endWriting(m_writer.get());
 }
 
 DEFINE_WEAK_IDENTIFIER_MAP(DocumentLoader);
 
 } // namespace blink