[MemoryCache] Split UMAs for RevalidationPolicy for preloading/regular requests

third_party/WebKit/Source/core/fetch/ResourceFetcher.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) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
     Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
 
     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 373 matching lines @@
         resource = preCacheData(request, factory, substituteData);
     if (!resource)
         resource = memoryCache()->resourceForURL(url, getCacheIdentifier());
 
     // See if we can use an existing resource from the cache. If so, we need to move it to be load blocking.
     moveCachedNonBlockingResourceToBlocking(resource.get(), request);
 
     const RevalidationPolicy policy = determineRevalidationPolicy(factory.type(), request, resource.get(), isStaticData);
 
     String histogramName = "Blink.MemoryCache.RevalidationPolicy.";
+    if (request.forPreload())
+        histogramName.append("Preload.");
     histogramName.append(Resource::resourceTypeName(factory.type()));
     Platform::current()->histogramEnumeration(histogramName.utf8().data(), policy, Load + 1);
 
     switch (policy) {
     case Reload:
         memoryCache()->remove(resource.get());
         // Fall through
     case Load:
         resource = createResourceForLoading(request, request.charset(), factory);
         break;
@@ skipping 762 matching lines @@
     visitor->trace(m_loaders);
     visitor->trace(m_nonBlockingLoaders);
 #if ENABLE(OILPAN)
     visitor->trace(m_documentResources);
     visitor->trace(m_preloads);
     visitor->trace(m_resourceTimingInfoMap);
 #endif
 }
 
 } // namespace blink