Ensure visual overflow from style recalc gets propagated

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

Index: third_party/WebKit/Source/core/layout/LayoutBlock.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index 496270a86f26fc7fbbe7b88ac937066e5b3fc381..f85dc3527cdab89f33e87a2ba7dc8c8ac4fd28f4 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -2066,7 +2066,7 @@ bool LayoutBlock::RecalcOverflowAfterStyleChange() {
   if (HasOverflowClip())
     Layer()->GetScrollableArea()->UpdateAfterOverflowRecalc();
 
-  return !HasOverflowClip();
+  return true;

[Xianzhu, 2017/05/23 20:35:42]

To keep the optimization for child overflow change not affecting overflow of
ancestors, I think this should be changed to:
  return !HasOverflowClip() || self_needs_overflow_recalc;
(with
   bool self_needed_overflow_recalc = SelfNeedsOverflowRecalcStyleChange()
 inserted before line 2052).

[rhogan, 2017/05/23 21:32:17]

OK, done!

 }
 
 // Called when a positioned object moves but doesn't necessarily change size.