[tracing] Fix accounting of WebCache memory statistics

public/web/WebCache.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 36 matching lines @@
         size_t liveSize;
         size_t deadSize;
     };
 
     // A struct mirroring blink::MemoryCache::TypeStatistic.
     struct ResourceTypeStat {
         size_t count;
         size_t size;
         size_t liveSize;
         size_t decodedSize;
+        size_t purgedSize;
+        size_t purgeableSize;
     };
 
     // A struct mirroring blink::MemoryCache::Statistics.
     struct ResourceTypeStats {
         ResourceTypeStat images;
         ResourceTypeStat cssStyleSheets;
         ResourceTypeStat scripts;
         ResourceTypeStat xslStyleSheets;
         ResourceTypeStat fonts;
         ResourceTypeStat other;
@@ skipping 19 matching lines @@
     // cleared if they are actively referenced). And releases cache memory.
     BLINK_EXPORT static void pruneAll();
 
 private:
     WebCache();  // Not intended to be instanced.
 };
 
 }  // namespace blink
 
 #endif