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

Source/core/html/LinkResource.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 27 matching lines @@
 
 namespace WebCore {
 
 class HTMLLinkElement;
 
 class LinkResource : public NoBaseWillBeGarbageCollectedFinalized<LinkResource>  {
     WTF_MAKE_NONCOPYABLE(LinkResource); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
     enum Type {
         Style,
-        Import
+        Import,
+        Manifest
     };
 
     explicit LinkResource(HTMLLinkElement*);
     virtual ~LinkResource();
 
     bool shouldLoadResource() const;
     LocalFrame* loadingFrame() const;
 
     virtual Type type() const = 0;
     virtual void process() = 0;
@@ skipping 17 matching lines @@
 
 private:
     HTMLLinkElement* m_owner;
     KURL m_url;
     AtomicString m_charset;
 };
 
 } // namespace WebCore
 
 #endif // LinkResource_h