Add UMA to estimate deroppable memory usage of encoded data size in Resources

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

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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
@@ skipping 384 matching lines @@
 
   SharedBuffer* data() const { return m_data.get(); }
   void clearData();
 
   class ProhibitAddRemoveClientInScope : public AutoReset<bool> {
    public:
     ProhibitAddRemoveClientInScope(Resource* resource)
         : AutoReset(&resource->m_isAddRemoveClientProhibited, true) {}
   };
 
+  bool isReloadable() const;

[yhirano, 2016/11/15 10:21:55]

What does this method mean?

[hajimehoshi, 2016/11/15 10:50:07]

This returns true when the resource can be reloaded. For example, if the image
is used as CSS background, it is difficult to load the encoded data from the
disk cache in the current implementation, and this function returns false in
this case.

+
  private:
   class ResourceCallback;
   class CachedMetadataHandlerImpl;
   class ServiceWorkerResponseCachedMetadataHandler;
 
   void cancelTimerFired(TimerBase*);
 
   void revalidationSucceeded(const ResourceResponse&);
   void revalidationFailed();
 
@@ skipping 78 matching lines @@
 };
 
 #define DEFINE_RESOURCE_TYPE_CASTS(typeName)                   \
   DEFINE_TYPE_CASTS(typeName##Resource, Resource, resource,    \
                     resource->getType() == Resource::typeName, \
                     resource.getType() == Resource::typeName);
 
 }  // namespace blink
 
 #endif