Avoid sending mixed-content requests for ImageSet contexts

third_party/WebKit/Source/core/loader/LinkLoader.cpp

 /*
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 307 matching lines @@
     return nullptr;
   }
 
   if (!IsSupportedType(resource_type.value(), mime_type)) {
     document.AddConsoleMessage(ConsoleMessage::Create(
         kOtherMessageSource, kWarningMessageLevel,
         String("<link rel=preload> has an unsupported `type` value")));
     return nullptr;
   }
   ResourceRequest resource_request(document.CompleteURL(href));
-  resource_request.SetRequestContext(
-      ResourceFetcher::DetermineRequestContext(resource_type.value(), false));
+  resource_request.SetRequestContext(ResourceFetcher::DetermineRequestContext(
+      resource_type.value(), ResourceFetcher::kImageNotImageSet, false));
 
   if (referrer_policy != kReferrerPolicyDefault) {
     resource_request.SetHTTPReferrer(SecurityPolicy::GenerateReferrer(
         referrer_policy, href, document.OutgoingReferrer()));
   }
 
   FetchParameters link_fetch_params(
       resource_request, FetchInitiatorTypeNames::link, document.EncodingName());
 
   if (cross_origin != kCrossOriginAttributeNotSet) {
@@ skipping 158 matching lines @@
 
 DEFINE_TRACE(LinkLoader) {
   visitor->Trace(client_);
   visitor->Trace(prerender_);
   visitor->Trace(link_preload_resource_client_);
   ResourceOwner<Resource, ResourceClient>::Trace(visitor);
   PrerenderClient::Trace(visitor);
 }
 
 }  // namespace blink