Revert of Prerender: Disable prefetch if there's an appcache.

third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp

 /*
  * 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 865 matching lines @@
 
   // We should never reach this point if we're using a parser thread, as
   // appendBytes() will directly ship the data to the thread.
   DCHECK(!shouldUseThreading());
 
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("blink.debug"),
                "HTMLDocumentParser::append", "size", inputSource.length());
   const SegmentedString source(inputSource);
 
   if (document()->isPrefetchOnly()) {
-    // Do not prefetch if there is an appcache.
-    if (document()->loader()->response().appCacheID() != 0)
-      return;
-
     if (!m_preloadScanner)
       m_preloadScanner = createPreloadScanner();
 
     m_preloadScanner->appendToEnd(source);
     scanAndPreload(m_preloadScanner.get());
 
     // Return after the preload scanner, do not actually parse the document.
     return;
   }
 
@@ skipping 417 matching lines @@
     successHistogram.count(duration);
   } else {
     DEFINE_STATIC_LOCAL(
         CustomCountHistogram, failureHistogram,
         ("PreloadScanner.DocumentWrite.ExecutionTime.Failure", 1, 10000, 50));
     failureHistogram.count(duration);
   }
 }
 
 }  // namespace blink