Begin tracking why layout is invalidated

Source/core/layout/LayoutImage.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011-2012. All rights reserved.
  *
@@ skipping 139 matching lines @@
 
     // If the actual area occupied by the image has changed and it is not constrained by style then a layout is required.
     bool imageSizeIsConstrained = style()->logicalWidth().isSpecified() && style()->logicalHeight().isSpecified();
 
     // FIXME: We only need to recompute the containing block's preferred size if the containing block's size
     // depends on the image's size (i.e., the container uses shrink-to-fit sizing).
     // There's no easy way to detect that shrink-to-fit is needed, always force a layout.
     bool containingBlockNeedsToRecomputePreferredSize = style()->logicalWidth().isPercent() || style()->logicalMaxWidth().isPercent()  || style()->logicalMinWidth().isPercent();
 
     if (imageSourceHasChangedSize && (!imageSizeIsConstrained || containingBlockNeedsToRecomputePreferredSize)) {
-        setNeedsLayoutAndFullPaintInvalidation();
+        setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SizeChanged);
         return;
     }
 
     // The image hasn't changed in size or its style constrains its size, so a paint invalidation will suffice.
     if (everHadLayout() && !selfNeedsLayout()) {
         // The inner content rectangle is calculated during layout, but may need an update now
         // (unless the box has already been scheduled for layout). In order to calculate it, we
         // may need values from the containing block, though, so make sure that we're not too
         // early. It may be that layout hasn't even taken place once yet.
         updateInnerContentRect();
@@ skipping 217 matching lines @@
         return 0;
 
     ImageResource* cachedImage = m_imageResource->cachedImage();
     if (cachedImage && cachedImage->image() && cachedImage->image()->isSVGImage())
         return toSVGImage(cachedImage->image())->embeddedContentBox();
 
     return 0;
 }
 
 } // namespace blink