Rename FullscreenElementStack to just Fullscreen

Source/web/WebDocument.cpp

Index: Source/web/WebDocument.cpp
diff --git a/Source/web/WebDocument.cpp b/Source/web/WebDocument.cpp
index 0321635d4aa3e7421ddab61d7f137841408136ab..d2672d48fc37f8f1c0fd9ad845d2dcee82c9f1a9 100644
--- a/Source/web/WebDocument.cpp
+++ b/Source/web/WebDocument.cpp
@@ -41,7 +41,7 @@
 #include "core/dom/Document.h"
 #include "core/dom/DocumentType.h"
 #include "core/dom/Element.h"
-#include "core/dom/FullscreenElementStack.h"
+#include "core/dom/Fullscreen.h"
 #include "core/dom/StyleEngine.h"
 #include "core/html/HTMLAllCollection.h"
 #include "core/html/HTMLBodyElement.h"
@@ -229,14 +229,14 @@ void WebDocument::watchCSSSelectors(const WebVector<WebString>& webSelectors)
 
 void WebDocument::cancelFullScreen()
 {
-    if (FullscreenElementStack* fullscreen = FullscreenElementStack::fromIfExists(*unwrap<Document>()))
+    if (Fullscreen* fullscreen = Fullscreen::fromIfExists(*unwrap<Document>()))
         fullscreen->fullyExitFullscreen();
 }
 
 WebElement WebDocument::fullScreenElement() const
 {
     Element* fullScreenElement = 0;
-    if (FullscreenElementStack* fullscreen = FullscreenElementStack::fromIfExists(*const_cast<WebDocument*>(this)->unwrap<Document>()))
+    if (Fullscreen* fullscreen = Fullscreen::fromIfExists(*const_cast<WebDocument*>(this)->unwrap<Document>()))
         fullScreenElement = fullscreen->webkitCurrentFullScreenElement();
     return WebElement(fullScreenElement);
 }