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

Source/core/fetch/Resource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 938 matching lines @@
     case Resource::LinkSubresource:
         return "Link subresource";
     case Resource::TextTrack:
         return "Text track";
     case Resource::Shader:
         return "Shader";
     case Resource::ImportResource:
         return "Imported resource";
     case Resource::Media:
         return "Media";
+    case Resource::Manifest:
+        return "Manifest";
     }
     ASSERT_NOT_REACHED();
     return initatorTypeNameToString(initiatorInfo.name);
 }
 
 #if !LOG_DISABLED
 const char* ResourceTypeName(Resource::Type type)
 {
     switch (type) {
     case Resource::MainResource:
@@ skipping 17 matching lines @@
     case Resource::LinkSubresource:
         return "LinkSubresource";
     case Resource::TextTrack:
         return "TextTrack";
     case Resource::Shader:
         return "Shader";
     case Resource::ImportResource:
         return "ImportResource";
     case Resource::Media:
         return "Media";
+    case Resource::Manifest:
+        return "Manifest";
     }
     ASSERT_NOT_REACHED();
     return "Unknown";
 }
 #endif // !LOG_DISABLED
 
 }