Revert of Reland "Implement FullScreen using top layer."

third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp

Index: third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp b/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
index 125366cb0ae615e8c79079d5de0ed9bfe53dbced..cbd019ecde9092c02031f2f6e85802457d7e33c4 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
@@ -887,10 +887,7 @@ PseudoElement* StyleResolver::createPseudoElementIfNeeded(Element& parent, Pseud
     if (pseudoId == PseudoIdFirstLetter && (parent.isSVGElement() || !FirstLetterPseudoElement::firstLetterTextLayoutObject(parent)))
         return nullptr;
 
-    // The backdrop pseudo element generates a new stacking context and its
-    // layout object does not become a child of |parentLayoutObject|. The
-    // exemption is needed so that replaced content also gets a backdrop.
-    if (pseudoId != PseudoIdBackdrop && !canHaveGeneratedChildren(*parentLayoutObject))
+    if (!canHaveGeneratedChildren(*parentLayoutObject))
         return nullptr;
 
     ComputedStyle* parentStyle = parentLayoutObject->mutableStyle();