Check subtree paint invalidation when overflow clip status changes

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 316305c8422ab5c53f5d143851368bc1b25e1354..d5bee361778483630ea2d398bcafcbfda68e6899 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -245,8 +245,7 @@ void LayoutBlock::updateFromStyle()
     if (shouldClipOverflow != hasOverflowClip()) {
         if (!shouldClipOverflow)
             getScrollableArea()->invalidateAllStickyConstraints();
-        for (LayoutObject* child = firstChild(); child; child = child->nextSibling())

[chrishtr, 2016/05/23 20:10:32]

Even before https://crrev.com/392652 it was a bug though, right? Just harder to
exhibit?

[Xianzhu, 2016/05/23 21:35:49]

I think so, but couldn't create a test case to fail before 392652.

-            child->setMayNeedPaintInvalidation();
+        setMayNeedPaintInvalidationSubtree();
     }
     setHasOverflowClip(shouldClipOverflow);
 }