Adding or changing any of box-shadow, outline, or border-image-outset does not need a layout..

third_party/WebKit/Source/core/layout/LayoutTableRow.h

Index: third_party/WebKit/Source/core/layout/LayoutTableRow.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableRow.h b/third_party/WebKit/Source/core/layout/LayoutTableRow.h
index 9f7d669480fd987ba40a2afdd7475ce76e48e34f..4bbd5609c5b4e8a65b4958929040375efed69a9e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableRow.h
+++ b/third_party/WebKit/Source/core/layout/LayoutTableRow.h
@@ -122,7 +122,7 @@ public:
 
     bool nodeAtPoint(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) override;
 
-    void addOverflowFromCell(const LayoutTableCell*);
+    void computeOverflow();
 
     const char* name() const override { return "LayoutTableRow"; }
 
@@ -133,6 +133,7 @@ public:
     bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const override { return false; }
 
 private:
+    void addOverflowFromCell(const LayoutTableCell*);
     LayoutObjectChildList* virtualChildren() override { return children(); }
     const LayoutObjectChildList* virtualChildren() const override { return children(); }