Defer loads in new pages/frames if ScopedPageLoadDeferral is active

third_party/WebKit/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 257 matching lines @@
 
     if (m_applicationCacheHost)
         m_applicationCacheHost->failedLoadingMainResource();
     m_state = MainResourceDone;
     frameLoader()->loadFailed(this, m_mainResource->resourceError());
     clearMainResourceHandle();
 }
 
 void DocumentLoader::finishedLoading(double finishTime)
 {
-    ASSERT(!m_frame->page()->defersLoading() || InspectorInstrumentation::isDebuggerPaused(m_frame));
+    DCHECK(m_frame->loader().stateMachine()->creatingInitialEmptyDocument()

[dcheng, 2016/07/25 06:48:18]

This is called during FrameLoader::init() to create the initial empty document.
It "should" be OK to allow this, as the document will always be same origin.

+        || !m_frame->page()->defersLoading()
+        || InspectorInstrumentation::isDebuggerPaused(m_frame));
 
     double responseEndTime = finishTime;
     if (!responseEndTime)
         responseEndTime = m_timeOfLastDataReceived;
     if (!responseEndTime)
         responseEndTime = monotonicallyIncreasingTime();
     timing().setResponseEnd(responseEndTime);
 
     commitIfReady();
     if (!frameLoader())
@@ skipping 421 matching lines @@
 {
     m_writer = createWriterFor(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