ViewPainter should skip painting if not inside painting subtree

Source/core/paint/ViewPainter.cpp

Index: Source/core/paint/ViewPainter.cpp
diff --git a/Source/core/paint/ViewPainter.cpp b/Source/core/paint/ViewPainter.cpp
index 2af46f8b3073baa4bc497c7ae0df5421d4d30957..fd892d571a52e8ebc3a2a99f43c804adeaff4f20 100644
--- a/Source/core/paint/ViewPainter.cpp
+++ b/Source/core/paint/ViewPainter.cpp
@@ -31,6 +31,9 @@ void ViewPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffs
 
 void ViewPainter::paintBoxDecorationBackground(const PaintInfo& paintInfo)
 {
+    if (!paintInfo.shouldPaintWithinRoot(&m_layoutView))
+        return;
+
     if (paintInfo.skipRootBackground())
         return;