Revert "Implement FullScreen using top layer."

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 0070c4ac61c4b79cae6ead57274008eb9ae1315b..f3fb8fd67c586197aa30b4af20652bbe712f509d 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -5070,12 +5070,9 @@ void Document::removeFromTopLayer(Element* element)
 
 HTMLDialogElement* Document::activeModalDialog() const
 {
-    for (auto it = m_topLayerElements.rbegin(); it != m_topLayerElements.rend(); ++it) {
-        if (isHTMLDialogElement(*it))
-            return toHTMLDialogElement((*it).get());
-    }
-
-    return nullptr;
+    if (m_topLayerElements.isEmpty())
+        return 0;
+    return toHTMLDialogElement(m_topLayerElements.last().get());
 }
 
 void Document::exitPointerLock()