Remove webkitIsFullScreen everywhere except in bindings

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index 6b29facf87127577991879a6ace097e9a44ff59f..b2e91147ce635d4132727b17ed825571bf86d053 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -2969,7 +2969,7 @@ bool EventHandler::keyEvent(const PlatformKeyboardEvent& initialKeyEvent)
 
     ASSERT(m_frame->document());
     if (Fullscreen* fullscreen = Fullscreen::fromIfExists(*m_frame->document())) {
-        if (fullscreen->webkitIsFullScreen() && !isKeyEventAllowedInFullScreen(fullscreen, initialKeyEvent)) {
+        if (fullscreen->webkitCurrentFullScreenElement() && !isKeyEventAllowedInFullScreen(fullscreen, initialKeyEvent)) {
             UseCounter::count(*m_frame->document(), UseCounter::KeyEventNotAllowedInFullScreen);
             return false;
         }