Begin tracking why layout is invalidated

Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1693 matching lines @@
     // this condition in the future as we move renderer changes out of layout and into style changes.
     if (doesNotNeedLayoutOrPaintInvalidation)
         return;
 
     // Now that the layer (if any) has been updated, we need to adjust the diff again,
     // check whether we should layout now, and decide if we need to invalidate paints.
     StyleDifference updatedDiff = adjustStyleDifference(diff);
 
     if (!diff.needsFullLayout()) {
         if (updatedDiff.needsFullLayout())
-            setNeedsLayoutAndPrefWidthsRecalc();
+            setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::StyleChange);
         else if (updatedDiff.needsPositionedMovementLayout())
             setNeedsPositionedMovementLayout();
     }
 
     if (diff.transformChanged() && !needsLayout()) {
         if (LayoutBlock* container = containingBlock())
             container->setNeedsOverflowRecalcAfterStyleChange();
     }
 
     if (updatedDiff.needsPaintInvalidationLayer())
@@ skipping 127 matching lines @@
         // directly affect the containing block of this object is a change to
         // the position style.
         if (needsLayout() && oldStyle->position() != m_style->position())
             markContainerChainForLayout();
 
         // Ditto.
         if (needsOverflowRecalcAfterStyleChange() && oldStyle->position() != m_style->position())
             markContainingBlocksForOverflowRecalc();
 
         if (diff.needsFullLayout())
-            setNeedsLayoutAndPrefWidthsRecalc();
+            setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::StyleChange);
     } else if (diff.needsPositionedMovementLayout()) {
         setNeedsPositionedMovementLayout();
     }
 
     // Don't check for paint invalidation here; we need to wait until the layer has been
     // updated by subclasses before we know if we have to invalidate paints (in setStyle()).
 
     if (oldStyle && !areCursorsEqual(oldStyle, style())) {
         if (LocalFrame* frame = this->frame())
             frame->eventHandler().scheduleCursorUpdate();
@@ skipping 1353 matching lines @@
 {
     if (object1) {
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
     }
 }
 
 #endif