Begin tracking why layout is invalidated

Source/core/layout/LayoutObjectChildList.cpp

Index: Source/core/layout/LayoutObjectChildList.cpp
diff --git a/Source/core/layout/LayoutObjectChildList.cpp b/Source/core/layout/LayoutObjectChildList.cpp
index d317d1f4871a16fd46ac0563eb3292b77000c82f..ba2aecaa446a7dfc716ea310411101a0f4af2f47 100644
--- a/Source/core/layout/LayoutObjectChildList.cpp
+++ b/Source/core/layout/LayoutObjectChildList.cpp
@@ -65,7 +65,7 @@ LayoutObject* LayoutObjectChildList::removeChildNode(LayoutObject* owner, Layout
         // that a positioned child got yanked). We also issue paint invalidations, so that the area exposed when the child
         // disappears gets paint invalidated properly.
         if (!owner->documentBeingDestroyed() && notifyRenderer && oldChild->everHadLayout()) {
-            oldChild->setNeedsLayoutAndPrefWidthsRecalc();
+            oldChild->setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::RemovedFromLayout);
             invalidatePaintOnRemoval(*oldChild);
         }
     }
@@ -156,7 +156,7 @@ void LayoutObjectChildList::insertChildNode(LayoutObject* owner, LayoutObject* n
         LayoutCounter::rendererSubtreeAttached(newChild);
     }
 
-    newChild->setNeedsLayoutAndPrefWidthsRecalc();
+    newChild->setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::AddedToLayout);
     newChild->setShouldDoFullPaintInvalidation(PaintInvalidationRendererInsertion);
     if (!owner->normalChildNeedsLayout())
         owner->setChildNeedsLayout(); // We may supply the static position for an absolute positioned child.