Remove margin collapsing.

sky/engine/core/rendering/RenderBox.cpp

Index: sky/engine/core/rendering/RenderBox.cpp
diff --git a/sky/engine/core/rendering/RenderBox.cpp b/sky/engine/core/rendering/RenderBox.cpp
index 4c7a16ef4386f92b555172205ccfb58147673a73..1188048d9d1c199dc97c93da14ddf9a823691d39 100644
--- a/sky/engine/core/rendering/RenderBox.cpp
+++ b/sky/engine/core/rendering/RenderBox.cpp
@@ -3681,10 +3681,7 @@ LayoutRect RenderBox::layoutOverflowRectForPropagation(RenderStyle* parentStyle)
 {
     // Only propagate interior layout overflow if we don't clip it.
     LayoutRect rect = borderBoxRect();
-    // We want to include the margin, but only when it adds height. Quirky margins don't contribute height
-    // nor do the margins of self-collapsing blocks.
-    if (!style()->hasMarginAfterQuirk() && !isSelfCollapsingBlock())
-        rect.expand(LayoutSize(LayoutUnit(), marginAfter()));
+    rect.expand(LayoutSize(LayoutUnit(), marginAfter()));
 
     if (!hasOverflowClip())
         rect.unite(layoutOverflowRect());