Begin tracking why layout is invalidated

Source/core/layout/LayoutReplaced.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011-2012. 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 84 matching lines @@
 
     if (replacedContentRect() != oldContentRect)
         setShouldDoFullPaintInvalidation();
 }
 
 void LayoutReplaced::intrinsicSizeChanged()
 {
     int scaledWidth = static_cast<int>(defaultWidth * style()->effectiveZoom());
     int scaledHeight = static_cast<int>(defaultHeight * style()->effectiveZoom());
     m_intrinsicSize = LayoutSize(scaledWidth, scaledHeight);
-    setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation();
+    setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(LayoutInvalidationReason::SizeChanged);
 }
 
 void LayoutReplaced::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     ReplacedPainter(*this).paint(paintInfo, paintOffset);
 }
 
 bool LayoutReplaced::shouldPaint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset) const
 {
     if (paintInfo.phase != PaintPhaseForeground && paintInfo.phase != PaintPhaseOutline && paintInfo.phase != PaintPhaseSelfOutline
@@ skipping 389 matching lines @@
         return LayoutRect();
 
     // The selectionRect can project outside of the overflowRect, so take their union
     // for paint invalidation to avoid selection painting glitches.
     LayoutRect r = isSelected() ? localSelectionRect() : visualOverflowRect();
     mapRectToPaintInvalidationBacking(paintInvalidationContainer, r, paintInvalidationState);
     return r;
 }
 
 }