Phase III Step 1: Make ImageResourceContent manage its own ResourceStatus

third_party/WebKit/Source/platform/loader/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 322 matching lines @@
   // off and optionally bypassing the cache.
   // If reloading is started, this method returns a new Resource that is used
   // for reloading, and |this| should be no longer used.
   // Otherwise, this method returns nullptr.
   virtual Resource* reloadIfLoFiOrPlaceholderImage(
       ResourceFetcher*,
       ReloadLoFiOrPlaceholderPolicy) {
     return nullptr;
   }
 
+  // Do not cause any JavaScript calls or client/observer notifications.

[kouhei (in TOK), 2017/03/15 11:18:53]

Would you also document what the hook is for?
Also, "JavaScript calls or client/observer notifications are disallowed inside
callback."

[hiroshige, 2017/05/04 20:21:57]

Done.

+  virtual void notifyStartLoad() {}
+
   static const char* resourceTypeToString(
       Type,
       const AtomicString& fetchInitiatorName);
 
  protected:
   Resource(const ResourceRequest&, Type, const ResourceLoaderOptions&);
 
   virtual void checkNotify();
 
   void markClientFinished(ResourceClient*);
@@ skipping 150 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