Add initial link preload support

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 315 matching lines @@
 }
 
 ResourcePtr<Resource> ResourceFetcher::fetchLinkResource(Resource::Type type, FetchRequest& request)
 {
     ASSERT(type == Resource::LinkPrefetch || type == Resource::LinkSubresource);
     ASSERT(request.resourceRequest().frameType() == WebURLRequest::FrameTypeNone);
     request.mutableResourceRequest().setRequestContext(type == Resource::LinkPrefetch ? WebURLRequest::RequestContextPrefetch : WebURLRequest::RequestContextSubresource);
     return requestResource(type, request);
 }
 
+ResourcePtr<Resource> ResourceFetcher::fetchLinkPreloadResource(Resource::Type type, FetchRequest& request)
+{
+    // TODO(yoav): Enforce a LinkPreload context here, once we know we're adding one - https://github.com/whatwg/fetch/issues/36
+    ASSERT(request.resourceRequest().frameType() == WebURLRequest::FrameTypeNone);
+    determineRequestContext(request.mutableResourceRequest(), type);
+    return requestResource(type, request);
+}
+
 ResourcePtr<RawResource> ResourceFetcher::fetchRawResource(FetchRequest& request)
 {
     ASSERT(request.resourceRequest().frameType() == WebURLRequest::FrameTypeNone);
     ASSERT(request.resourceRequest().requestContext() != WebURLRequest::RequestContextUnspecified);
     return toRawResource(requestResource(Resource::Raw, request));
 }
 
 ResourcePtr<RawResource> ResourceFetcher::fetchMainResource(FetchRequest& request, const SubstituteData& substituteData)
 {
     ASSERT(request.resourceRequest().frameType() != WebURLRequest::FrameTypeNone);
@@ skipping 944 matching lines @@
     ResourceLoaderHost::trace(visitor);
 }
 
 ResourceFetcher* ResourceFetcher::toResourceFetcher(ResourceLoaderHost* host)
 {
     ASSERT(host->objectType() == ResourceLoaderHost::ResourceFetcherType);
     return static_cast<ResourceFetcher*>(host);
 }
 
 }