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

Source/core/html/LinkRelAttribute.cpp

 /*
  * Copyright (C) 2011 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 28 matching lines @@
 LinkRelAttribute::LinkRelAttribute(const String& rel)
     : m_iconType(InvalidIcon)
     , m_isStyleSheet(false)
     , m_isAlternate(false)
     , m_isDNSPrefetch(false)
     , m_isLinkPrefetch(false)
     , m_isLinkSubresource(false)
     , m_isLinkPrerender(false)
     , m_isLinkNext(false)
     , m_isImport(false)
+    , m_isManifest(false)
 {
     if (rel.isEmpty())
         return;
     String relCopy = rel;
     relCopy.replace('\n', ' ');
     Vector<String> list;
     relCopy.split(' ', list);
     Vector<String>::const_iterator end = list.end();
     for (Vector<String>::const_iterator it = list.begin(); it != end; ++it) {
         if (equalIgnoringCase(*it, "stylesheet")) {
@@ skipping 18 matching lines @@
         } else if (equalIgnoringCase(*it, "prerender")) {
             m_isLinkPrerender = true;
         } else if (equalIgnoringCase(*it, "next")) {
             m_isLinkNext = true;
         } else if (equalIgnoringCase(*it, "apple-touch-icon")) {
             if (RuntimeEnabledFeatures::touchIconLoadingEnabled())
                 m_iconType = TouchIcon;
         } else if (equalIgnoringCase(*it, "apple-touch-icon-precomposed")) {
             if (RuntimeEnabledFeatures::touchIconLoadingEnabled())
                 m_iconType = TouchPrecomposedIcon;
+        } else if (equalIgnoringCase(*it, "manifest")) {
+            m_isManifest = true;
         }
     }
 }
 
 }