Create CoreTabHelper, move remaining core TCW functionality into it.

chrome/browser/ui/fullscreen_controller.cc

Index: chrome/browser/ui/fullscreen_controller.cc
diff --git a/chrome/browser/ui/fullscreen_controller.cc b/chrome/browser/ui/fullscreen_controller.cc
index 4a90b84ca679ee33d7dcc764fafcea23107f114b..df2ee97b785fbcb08099cfe7b5e6af27ca70bd90 100644
--- a/chrome/browser/ui/fullscreen_controller.cc
+++ b/chrome/browser/ui/fullscreen_controller.cc
@@ -10,6 +10,7 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
+#include "chrome/browser/ui/tab_contents/core_tab_helper.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_switches.h"
@@ -277,7 +278,7 @@ bool FullscreenController::HandleUserPressedEscape() {
 
 void FullscreenController::NotifyTabOfFullscreenExitIfNecessary() {
   if (fullscreened_tab_)
-    fullscreened_tab_->ExitFullscreenMode();
+    fullscreened_tab_->core_tab_helper()->ExitFullscreenMode();
   else
     DCHECK_EQ(mouse_lock_state_, MOUSELOCK_NOT_REQUESTED);