Detect <link rel='manifest'> and notify embedder.

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 304 matching lines @@
     ScriptPromise createRejectedPromise(ExecutionContext*, ScriptValue);
     ScriptPromise addOneToPromise(ExecutionContext*, ScriptPromise);
 
     void trace(Visitor*);
 
     void startSpeechInput(Element*);
     void setValueForUser(Element*, const String&);
 
     String textSurroundingNode(Node*, int x, int y, unsigned long maxLength);
 
+    String manifestURL(Document*, ExceptionState&);
+
 private:
     explicit Internals(Document*);
     Document* contextDocument() const;
     LocalFrame* frame() const;
     Vector<String> iconURLs(Document*, int iconTypesMask) const;
     PassRefPtrWillBeRawPtr<ClientRectList> annotatedRegions(Document*, bool draggable, ExceptionState&);
 
     DocumentMarker* markerAt(Node*, const String& markerType, unsigned index, ExceptionState&);
     RefPtrWillBeMember<InternalRuntimeFlags> m_runtimeFlags;
     RefPtrWillBeMember<InternalProfilers> m_profilers;
 };
 
 } // namespace WebCore
 
 #endif