Index: include/AdblockPlus/ReferrerMapping.h
===================================================================
--- a/include/AdblockPlus/ReferrerMapping.h
+++ b/include/AdblockPlus/ReferrerMapping.h
@@ -22,14 +22,14 @@
 #include <map>
 #include <string>
 #include <vector>
+#include "FilterEngine.h"
 
 namespace AdblockPlus
 {
   /**
    * Stores a mapping between URLs and their referrers.
-   * This can be used to build a chain of referrers for any URL
-   * (see `BuildReferrerChain()`), which approximates the frame structure, see
-   * FilterEngine::Matches().
+   * This can be used to build a frame structure for any URL
+   * (see `BuildFrameStructure()`), it's useful for FilterEngine::Matches().
    */
   class ReferrerMapping
   {
@@ -46,20 +46,31 @@
      * Records the refferer for a URL.
      * @param url Request URL.
      * @param referrer Request referrer.
+     * @param requestType Request type.
      */
-    void Add(const std::string& url, const std::string& referrer);
+    void Add(const std::string& url, const std::string& referrer,
+      FilterEngine::ContentType requestType);
 
     /**
-     * Builds a chain of referrers for the supplied URL.
+     * Builds a frame structure for the supplied URL.
      * This should reconstruct a document's parent frame URLs.
      * @param url URL to build the chain for.
-     * @return List of URLs, starting with `url`.
+     * @return List of URLs, finishing with `url`.
      */
-    std::vector<std::string> BuildReferrerChain(const std::string& url) const;
+    std::vector<std::string> BuildFrameStructure(const std::string& url) const;
 
   private:
     const int maxCachedUrls;
-    std::map<std::string, std::string> mapping;
+    struct RequestInfo
+    {
+      RequestInfo(const std::string& referrerArg, FilterEngine::ContentType typeArg)
+        : referrer(referrerArg) , type(typeArg)
+      {
+      }
+      std::string referrer;
+      FilterEngine::ContentType type;
+    };
+    std::map</*url*/std::string, RequestInfo> mapping;
     std::list<std::string> cachedUrls;
   };
 }