Images from content:url() aren't loading if the alt attribute is present

Source/core/html/HTMLImageElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 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 28 matching lines @@
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLImageFallbackHelper.h"
 #include "core/html/HTMLSourceElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/html/parser/HTMLSrcsetParser.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/layout/LayoutBlockFlow.h"
 #include "core/layout/LayoutImage.h"
 #include "core/page/Page.h"
+#include "core/style/ContentData.h"
 #include "platform/ContentType.h"
 #include "platform/EventDispatchForbiddenScope.h"
 #include "platform/MIMETypeRegistry.h"
 #include "platform/RuntimeEnabledFeatures.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 class HTMLImageElement::ViewportChangeListener final : public MediaQueryListListener {
@@ skipping 264 matching lines @@
         ImageCandidate candidate = bestFitSourceForSrcsetAttribute(document().devicePixelRatio(), sourceSize(*source), source->fastGetAttribute(srcsetAttr), &document());
         if (candidate.isEmpty())
             continue;
         return candidate;
     }
     return ImageCandidate();
 }
 
 LayoutObject* HTMLImageElement::createLayoutObject(const ComputedStyle& style)
 {
+    const ContentData* contentData = style.contentData();
+    if (contentData && contentData->isImage() && !toImageContentData(contentData)->image()->cachedImage()->errorOccurred())
+        return LayoutObject::createObject(this, style);
+
     if (m_useFallbackContent)
         return new LayoutBlockFlow(this);
 
-    if (style.hasContent())
-        return LayoutObject::createObject(this, style);
-
     LayoutImage* image = new LayoutImage(this);
     image->setImageResource(LayoutImageResource::create());
     image->setImageDevicePixelRatio(m_imageDevicePixelRatio);
     return image;
 }
 
 void HTMLImageElement::attach(const AttachContext& context)
 {
     HTMLElement::attach(context);
 
@@ skipping 343 matching lines @@
 const KURL& HTMLImageElement::sourceURL() const
 {
     return cachedImage()->response().url();
 }
 
 void HTMLImageElement::didAddUserAgentShadowRoot(ShadowRoot&)
 {
     HTMLImageFallbackHelper::createAltTextShadowTree(*this);
 }
 
+void HTMLImageElement::ensureFallbackForGeneratedContent()
+{
+    setUseFallbackContent();
+    reattachFallbackContent();
+}
+
 void HTMLImageElement::ensureFallbackContent()
 {
     if (m_useFallbackContent || m_isFallbackImage)
         return;
     setUseFallbackContent();
     reattachFallbackContent();
 }
 
 void HTMLImageElement::ensurePrimaryContent()
 {
@@ skipping 33 matching lines @@
     ensureUserAgentShadowRoot();
 }
 
 bool HTMLImageElement::isOpaque() const
 {
     Image* image = const_cast<HTMLImageElement*>(this)->imageContents();
     return image && image->currentFrameKnownToBeOpaque();
 }
 
 }