Reland: Make the HTMLDocumentParser yield more aggressively

Source/core/html/parser/HTMLDocumentParser.h

 /*
  * Copyright (C) 2010 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 178 matching lines @@
     XSSAuditor m_xssAuditor;
     XSSAuditorDelegate m_xssAuditorDelegate;
 
     // FIXME: m_lastChunkBeforeScript, m_tokenizer, m_token, and m_input should be combined into a single state object
     // so they can be set and cleared together and passed between threads together.
     OwnPtr<ParsedChunk> m_lastChunkBeforeScript;
     Deque<OwnPtr<ParsedChunk>> m_speculations;
     WeakPtrFactory<HTMLDocumentParser> m_weakFactory;
     WeakPtr<BackgroundHTMLParser> m_backgroundParser;
     OwnPtrWillBeMember<HTMLResourcePreloader> m_preloader;
+    PreloadRequestStream m_queuedPreloads;
 
     bool m_isPinnedToMainThread;
     bool m_endWasDelayed;
     bool m_haveBackgroundParser;
     unsigned m_pumpSessionNestingLevel;
 };
 
 }
 
 #endif