Make Fullscreen::requestFullscreen and exitFullscreen static

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

Index: third_party/WebKit/Source/core/dom/ElementFullscreen.cpp
diff --git a/third_party/WebKit/Source/core/dom/ElementFullscreen.cpp b/third_party/WebKit/Source/core/dom/ElementFullscreen.cpp
index 139a5fe3443bb595eea04cc92e8854340ab3f307..1cae9fca6d34e888bc592f8424f59d32f92d94bf 100644
--- a/third_party/WebKit/Source/core/dom/ElementFullscreen.cpp
+++ b/third_party/WebKit/Source/core/dom/ElementFullscreen.cpp
@@ -11,14 +11,14 @@ namespace blink {
 
 void ElementFullscreen::requestFullscreen(Element& element)
 {
-    Fullscreen::from(element.document()).requestFullscreen(element, Fullscreen::UnprefixedRequest);
+    Fullscreen::requestFullscreen(element, Fullscreen::UnprefixedRequest);
 }
 
 void ElementFullscreen::webkitRequestFullscreen(Element& element)
 {
     if (element.isInShadowTree())
         UseCounter::count(element.document(), UseCounter::PrefixedElementRequestFullscreenInShadow);
-    Fullscreen::from(element.document()).requestFullscreen(element, Fullscreen::PrefixedRequest);
+    Fullscreen::requestFullscreen(element, Fullscreen::PrefixedRequest);
 }
 
 } // namespace blink