Remove duplication of encoded image data

third_party/WebKit/Source/core/fetch/ImageResource.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 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 26 matching lines @@
 namespace blink {
 
 class FetchRequest;
 class FloatSize;
 class ImageResourceObserver;
 class MemoryCache;
 class ResourceClient;
 class ResourceFetcher;
 class SecurityOrigin;
 
+// ImageResource class represents an image type resource.
+//
+// As for the lifetimes of m_image and m_data, see this document:
+// https://docs.google.com/document/d/1v0yTAZ6wkqX2U_M6BNIGUJpM1s0TIw1VsqpxoL7aciY/edit?usp=sharing
 class CORE_EXPORT ImageResource final : public Resource, public ImageObserver, public MultipartImageResourceParser::Client {
     friend class MemoryCache;
     USING_GARBAGE_COLLECTED_MIXIN(ImageResource);
 public:
     using ClientType = ResourceClient;
 
     static ImageResource* fetch(FetchRequest&, ResourceFetcher*);
 
     static ImageResource* create(blink::Image* image)
     {
@@ skipping 37 matching lines @@
     void didAddClient(ResourceClient*) override;
 
     void addObserver(ImageResourceObserver*);
     void removeObserver(ImageResourceObserver*);
     bool hasClientsOrObservers() const override { return Resource::hasClientsOrObservers() || !m_observers.isEmpty() || !m_finishedObservers.isEmpty(); }
 
     ResourcePriority priorityFromObservers() override;
 
     void allClientsAndObserversRemoved() override;
 
+    PassRefPtr<SharedBuffer> resourceBuffer() const override;
     void appendData(const char*, size_t) override;
     void error(const ResourceError&) override;
     void responseReceived(const ResourceResponse&, std::unique_ptr<WebDataConsumerHandle>) override;
     void finish(double finishTime = 0.0) override;
 
     // For compatibility, images keep loading even if there are HTTP errors.
     bool shouldIgnoreHTTPStatusCodeErrors() const override { return true; }
 
     bool isImage() const override { return true; }
 
@@ skipping 60 matching lines @@
     bool m_hasDevicePixelRatioHeaderValue;
     HashCountedSet<ImageResourceObserver*> m_observers;
     HashCountedSet<ImageResourceObserver*> m_finishedObservers;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(Image);
 
 } // namespace blink
 
 #endif