[ImageResource 4] Split ImageResource into Resource and Image parts

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

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ImageResourceContentInterface_h
+#define ImageResourceContentInterface_h
+
+#include "core/CoreExport.h"
+#include "platform/graphics/Image.h"
+#include "platform/network/ResourceLoadPriority.h"
+
+namespace blink {
+
+class ImageResourceInfo;
+
+// Interface of ImageResourceContent visible to ImageResource.
+class CORE_EXPORT ImageResourceContentInterface : public GarbageCollectedMixin {

[hiroshige, 2016/11/30 06:46:24]

I introduced ImageResourceContentInterface in the hope to
1. Clarify what methods of ImageResourceContent are called from ImageResource
(to help further separation of them), and
2. Remove dependency from ImageResource to ImageResourceContent, and possibly
move ImageResource and ImageResourceContentInterface to platform and
ImageResourceContent to core/loader or somewhere.

However, we anyway need to obtain ImageResourceContent from ImageResource when
we get ImageResource from MemoryCache, so ImageResource need to have references
to ImageResourceContent, therefore the Goal 2. is not directly achieved.
For code simplicity, it might better to merge ImageResourceContentInterface and
ImageResourceContent again to reduce the number of classes.

toyoshim@, do you have any thoughts in terms of platform loading?

+ public:
+  enum ClearImageOption { ClearExistingImage, KeepExistingImage };
+
+  virtual void setImageResourceInfo(ImageResourceInfo*) = 0;
+  virtual void updateImage(PassRefPtr<SharedBuffer>,
+                           ClearImageOption,
+                           bool allDataReceived) = 0;
+  virtual void destroyDecodedData() = 0;
+  virtual void doResetAnimation() = 0;
+
+  virtual ResourcePriority priorityFromObservers() const = 0;
+  virtual bool hasObservers() const = 0;
+  virtual bool isSizeAvailable() const = 0;
+  virtual bool isRefetchableDataFromDiskCache() const = 0;
+  virtual blink::Image* getImage() const = 0;
+  virtual bool hasImage() const = 0;
+  DEFINE_INLINE_VIRTUAL_TRACE() {}
+};
+
+}  // namespace blink
+
+#endif