Rename FullscreenElementStack to just Fullscreen

Source/core/rendering/compositing/RenderLayerCompositor.cpp

Index: Source/core/rendering/compositing/RenderLayerCompositor.cpp
diff --git a/Source/core/rendering/compositing/RenderLayerCompositor.cpp b/Source/core/rendering/compositing/RenderLayerCompositor.cpp
index f1452321b901ea3f62fcf7e2c27b4b14e583bc27..83bfd0653b6c5b76b43f0c44c2ed9b3e506a5ac6 100644
--- a/Source/core/rendering/compositing/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/compositing/RenderLayerCompositor.cpp
@@ -28,7 +28,7 @@
 #include "core/rendering/compositing/RenderLayerCompositor.h"
 
 #include "core/animation/DocumentAnimations.h"
-#include "core/dom/FullscreenElementStack.h"
+#include "core/dom/Fullscreen.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
@@ -166,16 +166,16 @@ bool RenderLayerCompositor::acceleratedCompositingForOverflowScrollEnabled() con
 static RenderVideo* findFullscreenVideoRenderer(Document& document)
 {
     // Recursively find the document that is in fullscreen.
-    Element* fullscreenElement = FullscreenElementStack::fullscreenElementFrom(document);
+    Element* fullscreenElement = Fullscreen::fullscreenElementFrom(document);
     Document* contentDocument = &document;
     while (fullscreenElement && fullscreenElement->isFrameOwnerElement()) {
         contentDocument = toHTMLFrameOwnerElement(fullscreenElement)->contentDocument();
         if (!contentDocument)
             return 0;
-        fullscreenElement = FullscreenElementStack::fullscreenElementFrom(*contentDocument);
+        fullscreenElement = Fullscreen::fullscreenElementFrom(*contentDocument);
     }
     // Get the current fullscreen element from the document.
-    fullscreenElement = FullscreenElementStack::currentFullScreenElementFrom(*contentDocument);
+    fullscreenElement = Fullscreen::currentFullScreenElementFrom(*contentDocument);
     if (!isHTMLVideoElement(fullscreenElement))
         return 0;
     RenderObject* renderer = fullscreenElement->renderer();