Preload scan external CSS for @import

third_party/WebKit/Source/core/fetch/Resource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 643 matching lines @@
         return true;
     if (type == Resource::CSSStyleSheet)
         return true;
     if (type == Resource::Script)
         return true;
     if (type == Resource::Font)
         return true;
     return false;
 }
 
-void Resource::willAddClientOrObserver()
+void Resource::willAddClientOrObserver(PreloadReferencePolicy policy)
 {
-    if (m_preloadResult == PreloadNotReferenced) {
+    if (policy == MarkAsReferenced && m_preloadResult == PreloadNotReferenced) {
         if (isLoaded())
             m_preloadResult = PreloadReferencedWhileComplete;
         else if (isLoading())
             m_preloadResult = PreloadReferencedWhileLoading;
         else
             m_preloadResult = PreloadReferenced;
 
         if (m_preloadDiscoveryTime) {
             int timeSinceDiscovery = static_cast<int>(1000 * (monotonicallyIncreasingTime() - m_preloadDiscoveryTime));
             DEFINE_STATIC_LOCAL(CustomCountHistogram, preloadDiscoveryHistogram, ("PreloadScanner.ReferenceTime", 0, 10000, 50));
             preloadDiscoveryHistogram.count(timeSinceDiscovery);
         }
     }
     if (!hasClientsOrObservers())
         memoryCache()->makeLive(this);
 }
 
-void Resource::addClient(ResourceClient* client)
+void Resource::addClient(ResourceClient* client, PreloadReferencePolicy policy)
 {
-    willAddClientOrObserver();
+    willAddClientOrObserver(policy);
 
     if (m_isRevalidating) {
         m_clients.add(client);
         return;
     }
 
     // If we have existing data to send to the new client and the resource type supprts it, send it asynchronously.
     if (!m_response.isNull() && !shouldSendCachedDataSynchronouslyForType(getType()) && !m_needsSynchronousCacheHit) {
         m_clientsAwaitingCallback.add(client);
         ResourceCallback::callbackHandler().schedule(this);
@@ skipping 368 matching lines @@
     case Resource::TextTrack:
     case Resource::Media:
     case Resource::Manifest:
         return false;
     }
     ASSERT_NOT_REACHED();
     return false;
 }
 
 } // namespace blink