Add a warning whenever link preloads are not used

third_party/WebKit/Source/core/loader/FrameFetchContext.h

 /*
  * Copyright (C) 2013 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 79 matching lines @@
 
     bool isControlledByServiceWorker() const override;
     int64_t serviceWorkerID() const override;
 
     bool isMainFrame() const override;
     bool defersLoading() const override;
     bool isLoadComplete() const override;
     bool pageDismissalEventBeingDispatched() const override;
     bool updateTimingInfoForIFrameNavigation(ResourceTimingInfo*) override;
     void sendImagePing(const KURL&) override;
-    void addConsoleMessage(const String&) const override;
+    void addConsoleMessage(const String&, MessageLevel = ErrorMessageLevel) const override;
     SecurityOrigin* getSecurityOrigin() const override;
     void upgradeInsecureRequest(ResourceRequest&) override;
     void addClientHintsIfNecessary(FetchRequest&) override;
     void addCSPHeaderIfNecessary(Resource::Type, FetchRequest&) override;
     void populateRequestData(ResourceRequest&) override;
 
     MHTMLArchive* archive() const override;
 
     ResourceLoadPriority modifyPriorityForExperiments(ResourceLoadPriority) override;
 
@@ skipping 20 matching lines @@
     // FIXME: Oilpan: Ideally this should just be a traced Member but that will
     // currently leak because ComputedStyle and its data are not on the heap.
     // See crbug.com/383860 for details.
     WeakMember<Document> m_document;
     Member<DocumentLoader> m_documentLoader;
 };
 
 } // namespace blink
 
 #endif