Enable HTMLImageElement to avoid immediate src loading when parsed

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 144 matching lines @@
     } else if (name == srcAttr || name == srcsetAttr) {
         if (RuntimeEnabledFeatures::srcsetEnabled()) {
             ImageCandidate candidate = bestFitSourceForImageAttributes(document().devicePixelRatio(), fastGetAttribute(srcAttr), fastGetAttribute(srcsetAttr));
             m_bestFitImageURL = candidate.toAtomicString();
             float candidateScaleFactor = candidate.scaleFactor();
             if (candidateScaleFactor > 0)
                 m_imageDevicePixelRatio = 1 / candidateScaleFactor;
             if (renderer() && renderer()->isImage())
                 toRenderImage(renderer())->setImageDevicePixelRatio(m_imageDevicePixelRatio);
         }
-        m_imageLoader.updateFromElementIgnoringPreviousError();
+        if (!m_parserSet)
+            m_imageLoader.updateFromElementIgnoringPreviousError();
     }
     else if (name == usemapAttr)
         setIsLink(!value.isNull());
     else if (name == onbeforeloadAttr)
         setAttributeEventListener(EventTypeNames::beforeload, createAttributeEventListener(this, name, value));
     else if (name == compositeAttr) {
         // FIXME: images don't support blend modes in their compositing attribute.
         blink::WebBlendMode blendOp = blink::WebBlendModeNormal;
         if (!parseCompositeAndBlendOperator(value, m_compositeOperator, blendOp))
             m_compositeOperator = CompositeSourceOver;
@@ skipping 227 matching lines @@
 
     return m_imageLoader.image()->image();
 }
 
 bool HTMLImageElement::isInteractiveContent() const
 {
     return fastHasAttribute(usemapAttr);
 }
 
 }