Add position: sticky as supported position value when CSSStickyPosition is enabled.

Source/core/layout/LayoutObject.cpp

Index: Source/core/layout/LayoutObject.cpp
diff --git a/Source/core/layout/LayoutObject.cpp b/Source/core/layout/LayoutObject.cpp
index 16ac690af84b0a27f460326e1de36c246c25bb80..0c2eda9270cb0b8fc461693ba9dd532f96517c23 100644
--- a/Source/core/layout/LayoutObject.cpp
+++ b/Source/core/layout/LayoutObject.cpp
@@ -1093,6 +1093,8 @@ String LayoutObject::decoratedName() const
         name.append(" (positioned)");
     if (isRelPositioned())
         name.append(" (relative positioned)");
+    if (isStickyPositioned())
+        name.append(" (sticky positioned)");
     if (isFloating())
         name.append(" (floating)");
     if (spannerPlaceholder())
@@ -2003,7 +2005,7 @@ void LayoutObject::propagateStyleToAnonymousChildren(bool blockChildrenOnly)
 
         // Preserve the position style of anonymous block continuations as they can have relative position when
         // they contain block descendants of relative positioned inlines.
-        if (child->isRelPositioned() && toLayoutBlock(child)->isAnonymousBlockContinuation())
+        if (child->isInFlowPositioned() && toLayoutBlock(child)->isAnonymousBlockContinuation())
             newStyle->setPosition(child->style()->position());
 
         updateAnonymousChildStyle(*child, *newStyle);