Add Web Resources usage to chrome://tracing.

third_party/WebKit/Source/core/fetch/MemoryCache.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 
     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
     version 2 of the License, or (at your option) any later version.
 
@@ skipping 10 matching lines @@
     This class provides all functionality needed for loading images, style sheets and html
     pages from the web. It has a memory cache for these objects.
 */
 
 #ifndef MemoryCache_h
 #define MemoryCache_h
 
 #include "core/CoreExport.h"
 #include "core/fetch/Resource.h"
 #include "core/fetch/ResourcePtr.h"
+#include "public/platform/WebMemoryDumpProvider.h"
 #include "public/platform/WebThread.h"
 #include "wtf/Allocator.h"
 #include "wtf/HashMap.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/Vector.h"
 #include "wtf/text/StringHash.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink  {
 
@@ skipping 185 matching lines @@
     MemoryCacheLiveResourcePriority priority(Resource*) const;
 
     // TaskObserver implementation
     void willProcessTask() override;
     void didProcessTask() override;
 
     void pruneAll();
 
     void updateFramePaintTimestamp();
 
+    // Take memory usage snapshot for tracing.
+    void onMemoryDump(WebProcessMemoryDump*);
+
 private:
     enum PruneStrategy {
         // Automatically decide how much to prune.
         AutomaticPrune,
         // Maximally prune resources.
         MaximalPrune
     };
 
     MemoryCache();
 
@@ skipping 79 matching lines @@
 // Returns the global cache.
 CORE_EXPORT MemoryCache* memoryCache();
 
 // Sets the global cache, used to swap in a test instance. Returns the old
 // MemoryCache object.
 CORE_EXPORT MemoryCache* replaceMemoryCacheForTesting(MemoryCache*);
 
 }
 
 #endif