DO NOT SUBMIT really old prototype of sprite recognition for image replacement

third_party/WebKit/Source/core/css/resolver/ElementStyleResources.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google 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 10 matching lines @@
  */
 
 #include "core/css/resolver/ElementStyleResources.h"
 
 #include "core/CSSPropertyNames.h"
 #include "core/css/CSSCursorImageValue.h"
 #include "core/css/CSSGradientValue.h"
 #include "core/css/CSSImageValue.h"
 #include "core/css/CSSURIValue.h"
 #include "core/dom/Document.h"
+#include "core/fetch/ImageResource.h"
 #include "core/fetch/ResourceFetcher.h"
+#include "core/frame/Settings.h"
 #include "core/layout/svg/ReferenceFilterBuilder.h"
 #include "core/style/ComputedStyle.h"
 #include "core/style/ContentData.h"
 #include "core/style/CursorData.h"
 #include "core/style/FillLayer.h"
 #include "core/style/FilterOperation.h"
 #include "core/style/StyleFetchedImage.h"
 #include "core/style/StyleFetchedImageSet.h"
 #include "core/style/StyleGeneratedImage.h"
 #include "core/style/StyleImage.h"
 #include "core/style/StyleInvalidImage.h"
 #include "core/style/StylePendingImage.h"
+#include "platform/Length.h"
+#include "platform/LengthPoint.h"
 
 namespace blink {
 
 ElementStyleResources::ElementStyleResources(Document& document, float deviceScaleFactor)
     : m_document(&document)
     , m_deviceScaleFactor(deviceScaleFactor)
 {
 }
 
 StyleImage* ElementStyleResources::styleImage(CSSPropertyID property, const CSSValue& value)
@@ skipping 72 matching lines @@
             DocumentResource* resource = value->load(*m_document);
             if (!resource)
                 continue;
 
             // Stash the DocumentResource on the reference filter.
             ReferenceFilterBuilder::setDocumentResourceReference(referenceFilter, new DocumentResourceReference(resource));
         }
     }
 }
 
+static bool isSprite(const ComputedStyle& style)
+{
+    if (!style.hasBackgroundImage())
+        return false;
+
+    const FillLayer& background = style.backgroundLayers();
+    return (background.xPosition().isFixed() && !background.xPosition().isZero())
+        || (background.yPosition().isFixed() && !background.yPosition().isZero());
+}
+
+static ImageResource::PlaceholderRequestType determinePlaceholderRequestType(const Document& document, const ComputedStyle& style)
+{
+    return document.settings() && document.settings()->fetchImagePlaceholders() && !isSprite(style)
+        ? ImageResource::PlaceholderRequestType::AllowPlaceholder
+        : ImageResource::PlaceholderRequestType::DisallowPlaceholder;
+}
+
 StyleImage* ElementStyleResources::loadPendingImage(ComputedStyle* style, StylePendingImage* pendingImage, CrossOriginAttributeValue crossOrigin)
 {
     if (CSSImageValue* imageValue = pendingImage->cssImageValue())
-        return imageValue->cacheImage(*m_document, crossOrigin);
+        return imageValue->cacheImage(*m_document, crossOrigin, determinePlaceholderRequestType(*m_document, *style));
 
     if (CSSPaintValue* paintValue = pendingImage->cssPaintValue()) {
         StyleGeneratedImage* image = StyleGeneratedImage::create(*paintValue);
         style->addPaintImage(image);
         return image;
     }
 
     if (CSSImageGeneratorValue* imageGeneratorValue = pendingImage->cssImageGeneratorValue()) {
         imageGeneratorValue->loadSubimages(*m_document);
         return StyleGeneratedImage::create(*imageGeneratorValue);
     }
 
     if (CSSCursorImageValue* cursorImageValue = pendingImage->cssCursorImageValue())
         return cursorImageValue->cacheImage(*m_document, m_deviceScaleFactor);
 
     if (CSSImageSetValue* imageSetValue = pendingImage->cssImageSetValue())
-        return imageSetValue->cacheImage(*m_document, m_deviceScaleFactor, crossOrigin);
+        return imageSetValue->cacheImage(*m_document, m_deviceScaleFactor, crossOrigin, determinePlaceholderRequestType(*m_document, *style));
 
     ASSERT_NOT_REACHED();
     return nullptr;
 }
 
 void ElementStyleResources::loadPendingImages(ComputedStyle* style)
 {
     // We must loop over the properties and then look at the style to see if
     // a pending image exists, and only load that image. For example:
     //
@@ skipping 85 matching lines @@
     }
 }
 
 void ElementStyleResources::loadPendingResources(ComputedStyle* computedStyle)
 {
     loadPendingImages(computedStyle);
     loadPendingSVGDocuments(computedStyle);
 }
 
 } // namespace blink