HTML Imports: Teach preloader about HTML Imports.

Source/core/testing/Internals.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 72 matching lines @@
 
     static void resetToConsistentState(Page*);
 
     String elementLayoutTreeAsText(Element*, ExceptionState&);
 
     String address(Node*);
 
     GCObservation* observeGC(ScriptValue);
 
     bool isPreloaded(const String& url);
+    bool isPreloadedBy(const String& url, Document*);
     bool isLoadingFromMemoryCache(const String& url);
 
     bool isSharingStyle(Element*, Element*) const;
 
     PassRefPtrWillBeRawPtr<CSSStyleDeclaration> computedStyleIncludingVisitedInfo(Node*) const;
 
     PassRefPtrWillBeRawPtr<ShadowRoot> createUserAgentShadowRoot(Element* host);
 
     ShadowRoot* shadowRoot(Element* host);
     ShadowRoot* youngestShadowRoot(Element* host);
@@ skipping 265 matching lines @@
 
     DocumentMarker* markerAt(Node*, const String& markerType, unsigned index, ExceptionState&);
     Member<InternalRuntimeFlags> m_runtimeFlags;
 
     IterationSource* startIteration(ScriptState*, ExceptionState&) override;
 };
 
 } // namespace blink
 
 #endif // Internals_h