Rename FullscreenElementStack to just Fullscreen

Source/core/rendering/RenderInline.cpp

Index: Source/core/rendering/RenderInline.cpp
diff --git a/Source/core/rendering/RenderInline.cpp b/Source/core/rendering/RenderInline.cpp
index dd2490a087dcd10087e182537b653c0c0c601ed7..26f2b30cfc8cb1b9e3ca7c294818c1e1899eeb16 100644
--- a/Source/core/rendering/RenderInline.cpp
+++ b/Source/core/rendering/RenderInline.cpp
@@ -23,7 +23,7 @@
 #include "config.h"
 #include "core/rendering/RenderInline.h"
 
-#include "core/dom/FullscreenElementStack.h"
+#include "core/dom/Fullscreen.h"
 #include "core/dom/StyleEngine.h"
 #include "core/page/Chrome.h"
 #include "core/page/Page.h"
@@ -374,7 +374,7 @@ void RenderInline::splitInlines(RenderBlock* fromBlock, RenderBlock* toBlock,
     // that renderer is wrapped in a RenderFullScreen, so |this| is not its
     // parent. Since the splitting logic expects |this| to be the parent, set
     // |beforeChild| to be the RenderFullScreen.
-    if (FullscreenElementStack* fullscreen = FullscreenElementStack::fromIfExists(document())) {
+    if (Fullscreen* fullscreen = Fullscreen::fromIfExists(document())) {
         const Element* fullScreenElement = fullscreen->webkitCurrentFullScreenElement();
         if (fullScreenElement && beforeChild && beforeChild->node() == fullScreenElement)
             beforeChild = fullscreen->fullScreenRenderer();