Correct immersive mode gestures under rotation

chrome/browser/ui/views/frame/immersive_mode_controller_ash.h

Index: chrome/browser/ui/views/frame/immersive_mode_controller_ash.h
diff --git a/chrome/browser/ui/views/frame/immersive_mode_controller_ash.h b/chrome/browser/ui/views/frame/immersive_mode_controller_ash.h
index 15d004e04781489259c6eda826c39b4e7bea5547..16cc63f33119a4531c078e1f93c56434cadaa3e6 100644
--- a/chrome/browser/ui/views/frame/immersive_mode_controller_ash.h
+++ b/chrome/browser/ui/views/frame/immersive_mode_controller_ash.h
@@ -55,6 +55,10 @@ class ImmersiveModeControllerAsh : public ImmersiveModeController,
   // Shows the reveal view without any animations if immersive mode is enabled.
   void MaybeRevealWithoutAnimation();
 
+  // Call Add/RemovePreTargerHandler since the RootWindow or WindowObservers
+  // enabled state has changed.
+  void SetPreTargetHandler();
+
   // ImmersiveModeController overrides:
   virtual void Init(Delegate* delegate,
                     views::Widget* widget,