[NotLanded] Implement the fetching algorithm of the Web Manifest.

Source/web/WebLocalFrameImpl.h

 /*
  * Copyright (C) 2009 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 210 matching lines @@
 
     virtual WebString contentAsText(size_t maxChars) const OVERRIDE;
     virtual WebString contentAsMarkup() const OVERRIDE;
     virtual WebString renderTreeAsText(RenderAsTextControls toShow = RenderAsTextNormal) const OVERRIDE;
     virtual WebString markerTextForListItem(const WebElement&) const OVERRIDE;
     virtual WebRect selectionBoundsRect() const OVERRIDE;
 
     virtual bool selectionStartHasSpellingMarkerFor(int from, int length) const OVERRIDE;
     virtual WebString layerTreeAsText(bool showDebugInfo = false) const OVERRIDE;
 
+    virtual void requestManifest() OVERRIDE;
+
     // WebLocalFrame methods:
     virtual void addStyleSheetByURL(const WebString& url) OVERRIDE;
 
     void willDetachParent();
 
     static WebLocalFrameImpl* create(WebFrameClient*);
     virtual ~WebLocalFrameImpl();
 
     PassRefPtr<LocalFrame> initializeCoreFrame(FrameHost*, FrameOwner*, const AtomicString& name, const AtomicString& fallbackName);
 
@@ skipping 115 matching lines @@
     UserMediaClientImpl m_userMediaClientImpl;
 
     OwnPtrWillBePersistent<GeolocationClientProxy> m_geolocationClientProxy;
 };
 
 DEFINE_TYPE_CASTS(WebLocalFrameImpl, WebFrame, frame, frame->isWebLocalFrame(), frame.isWebLocalFrame());
 
 } // namespace blink
 
 #endif