[Offline Pages] Adding missing image/CSS detection in FrameSerializer.

third_party/WebKit/Source/core/frame/FrameSerializer.h

 /*
  * 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 33 matching lines @@
 
 class Attribute;
 class CSSRule;
 class CSSStyleSheet;
 class CSSValue;
 class Document;
 class Element;
 class FontResource;
 class ImageResourceContent;
 class LocalFrame;
+class Node;
 class SharedBuffer;
 class StylePropertySet;
 
 struct SerializedResource;
 
 // This class is used to serialize frame's contents back to text (typically
 // HTML).  It serializes frame's document and resources such as images and CSS
 // stylesheets.
 class CORE_EXPORT FrameSerializer final {
   STACK_ALLOCATED();
@@ skipping 36 matching lines @@
     // Tells whether to skip serialization of a subresource.
     virtual bool ShouldSkipResource(ResourceHasCacheControlNoStoreHeader) {
       return false;
     }
 
     // Returns custom attributes that need to add in order to serialize the
     // element.
     virtual Vector<Attribute> GetCustomAttributes(const Element&) {
       return Vector<Attribute>();
     }
+
+    // Visits a node during serialization.
+    virtual void VisitNode(const Node*) {}
   };
 
   // Constructs a serializer that will write output to the given deque of
   // SerializedResources and uses the Delegate for controlling some
   // serialization aspects.  Callers need to ensure that both arguments stay
   // alive until the FrameSerializer gets destroyed.
   FrameSerializer(Deque<SerializedResource>&, Delegate&);
 
   // Initiates the serialization of the frame. All serialized content and
   // retrieved resources are added to the Deque passed to the constructor.
@@ skipping 29 matching lines @@
   HashSet<KURL> resource_urls_;
 
   bool is_serializing_css_;
 
   Delegate& delegate_;
 };
 
 }  // namespace blink
 
 #endif  // FrameSerializer_h