HTML Imports: Teach preloader about HTML Imports.

Source/core/fetch/ResourceFetcher.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) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
     Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
 
     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 923 matching lines @@
 {
     return m_loaders ? m_loaders->size() : 0;
 }
 
 void ResourceFetcher::preload(Resource::Type type, FetchRequest& request, const String& charset)
 {
     // Ensure main resources aren't preloaded, since the cache can't actually reuse the preload.
     if (type == Resource::MainResource)
         return;
 
-    ASSERT(type == Resource::Script || type == Resource::CSSStyleSheet || type == Resource::Image);
+    ASSERT(type == Resource::Script || type == Resource::CSSStyleSheet || type == Resource::Image || type == Resource::ImportResource);
 
     String encoding;
-    if (type == Resource::Script || type == Resource::CSSStyleSheet) {
+    if (type == Resource::Script || type == Resource::CSSStyleSheet || type == Resource::ImportResource) {
         encoding = charset.isEmpty() ? context().charset() : charset;
 
         // RequestContext for Resource::Image is set in fetchImage below.
         determineRequestContext(request.mutableResourceRequest(), type);
     }
 
     request.setCharset(encoding);
     request.setForPreload(true);
 
     ResourcePtr<Resource> resource;
@@ skipping 333 matching lines @@
 
 DEFINE_TRACE(ResourceFetcher)
 {
     visitor->trace(m_context);
     visitor->trace(m_archiveResourceCollection);
     visitor->trace(m_loaders);
     visitor->trace(m_nonBlockingLoaders);
 }
 
 }