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

third_party/WebKit/Source/core/layout/LayoutObject.cpp

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index 051799571158e80164251832a3a2a3e5358c8d66..5b140a579dc9fd3338295218f7d4a30f0c64667e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -1923,10 +1923,16 @@ void LayoutObject::firstLineStyleDidChange(const ComputedStyle& oldStyle, const
         setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::StyleChange);
 }
 
-void LayoutObject::markContainingBlocksForOverflowRecalc()
+void LayoutObject::markAncestorsForOverflowRecalcIfNeeded()
 {
-    for (LayoutBlock* container = containingBlock(); container && !container->childNeedsOverflowRecalcAfterStyleChange(); container = container->containingBlock())
-        container->setChildNeedsOverflowRecalcAfterStyleChange();
+    LayoutObject* object = this;
+    do {
+        // Cell and row need to propagate the flag to their containing section and row as their containing block is the table wrapper.
+        // This enables us to only recompute overflow the modified sections / rows.
+        object = object->isTableCell() || object->isTableRow() ? object->parent() : object->containingBlock();
+        if (object)
+            object->setChildNeedsOverflowRecalcAfterStyleChange();
+    } while (object);
 }
 
 void LayoutObject::setNeedsOverflowRecalcAfterStyleChange()
@@ -1934,7 +1940,7 @@ void LayoutObject::setNeedsOverflowRecalcAfterStyleChange()
     bool neededRecalc = needsOverflowRecalcAfterStyleChange();
     setSelfNeedsOverflowRecalcAfterStyleChange();
     if (!neededRecalc)
-        markContainingBlocksForOverflowRecalc();
+        markAncestorsForOverflowRecalcIfNeeded();
 }
 
 void LayoutObject::setStyle(PassRefPtr<ComputedStyle> style)
@@ -2004,6 +2010,13 @@ void LayoutObject::setStyle(PassRefPtr<ComputedStyle> style)
             container->setNeedsOverflowRecalcAfterStyleChange();
     }
 
+    if (diff.visualOverflowChanged() && !needsLayout()) {
+        if (isLayoutBlock())
+            setNeedsOverflowRecalcAfterStyleChange();
+        else
+            setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::StyleChange);

[Xianzhu, 2016/03/22 17:02:05]

Nit: please add a TODO here and reference bug 437012.

+    }
+
     if (diff.needsPaintInvalidationLayer() || updatedDiff.needsPaintInvalidationLayer())
         setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants();
     else if (diff.needsPaintInvalidationObject() || updatedDiff.needsPaintInvalidationObject())
@@ -2104,7 +2117,7 @@ void LayoutObject::styleDidChange(StyleDifference diff, const ComputedStyle* old
 
         // Ditto.
         if (needsOverflowRecalcAfterStyleChange() && oldStyle->position() != m_style->position())
-            markContainingBlocksForOverflowRecalc();
+            markAncestorsForOverflowRecalcIfNeeded();
 
         setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::StyleChange);
     } else if (diff.needsPositionedMovementLayout()) {