Add a warning whenever link preloads are not used

third_party/WebKit/Source/core/frame/LocalDOMWindow.h

 /*
  * Copyright (C) 2006, 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 206 matching lines @@
     void removedEventListener(const AtomicString& eventType, const RegisteredEventListener&) override;
 
     // Protected DOMWindow overrides.
     void schedulePostMessage(MessageEvent*, PassRefPtr<SecurityOrigin> target, Document* source) override;
 
 private:
     // Intentionally private to prevent redundant checks when the type is
     // already LocalDOMWindow.
     bool isLocalDOMWindow() const override { return true; }
     bool isRemoteDOMWindow() const override { return false; }
+    void warnUnusedPreloads(TimerBase*);
 
     explicit LocalDOMWindow(LocalFrame&);
     void dispose();
 
     void dispatchLoadEvent();
     void clearDocument();
 
     void willDetachFrameHost();
 
     Member<LocalFrame> m_frame;
     Member<Document> m_document;
     Member<DOMVisualViewport> m_visualViewport;
+    Timer<LocalDOMWindow> m_unusedPreloadsTimer;
 
     bool m_shouldPrintWhenFinishedLoading;
 
     HeapHashSet<WeakMember<DOMWindowProperty>> m_properties;
 
     mutable Member<Screen> m_screen;
     mutable Member<History> m_history;
     mutable Member<BarProp> m_locationbar;
     mutable Member<BarProp> m_menubar;
     mutable Member<BarProp> m_personalbar;
@@ skipping 24 matching lines @@
 }
 
 inline String LocalDOMWindow::defaultStatus() const
 {
     return m_defaultStatus;
 }
 
 } // namespace blink
 
 #endif // LocalDOMWindow_h