Maintain child dependent ComputedStyle flags if propagation stops.

Source/core/style/ComputedStyle.h

Index: Source/core/style/ComputedStyle.h
diff --git a/Source/core/style/ComputedStyle.h b/Source/core/style/ComputedStyle.h
index 6ece4353b78f77cca16af6bc0c01be4cbb0e63db..dc16ed4d2c1664e592b4f82845b5574224f07057 100644
--- a/Source/core/style/ComputedStyle.h
+++ b/Source/core/style/ComputedStyle.h
@@ -1509,6 +1509,9 @@ public:
     void setHasExplicitlyInheritedProperties() { noninherited_flags.explicitInheritance = true; }
     bool hasExplicitlyInheritedProperties() const { return noninherited_flags.explicitInheritance; }
 
+    bool hasChildDependentFlags() const { return emptyState() || hasExplicitlyInheritedProperties(); }
+    void copyChildDependentFlagsFrom(const ComputedStyle&);
+
     bool hasBoxDecorations() const { return hasBorder() || hasBorderRadius() || hasOutline() || hasAppearance() || boxShadow() || hasFilter() || resize() != RESIZE_NONE; }
 
     bool borderObscuresBackground() const;