[ImageResource 4] Split ImageResource into Resource and Image parts

third_party/WebKit/Source/core/html/ImageDocument.h

Index: third_party/WebKit/Source/core/html/ImageDocument.h
diff --git a/third_party/WebKit/Source/core/html/ImageDocument.h b/third_party/WebKit/Source/core/html/ImageDocument.h
index c47b53a7cf6522716397a2d0ab11eb1c197ebdf6..c391bdc8a1588805e078d17dcf770a56be42d64e 100644
--- a/third_party/WebKit/Source/core/html/ImageDocument.h
+++ b/third_party/WebKit/Source/core/html/ImageDocument.h
@@ -41,7 +41,11 @@ class CORE_EXPORT ImageDocument final : public HTMLDocument {
     return new ImageDocument(initializer);
   }
 
-  ImageResource* cachedImage();
+  ImageResourceContent* cachedImage();
+
+  // TODO(hiroshige): Remove this.
+  ImageResource* cachedImageResourceDeprecated();
+
   HTMLImageElement* imageElement() const { return m_imageElement.get(); }
 
   void windowSizeChanged();