Adds ImmersiveContext and ImmersiveHandlerFactory

ash/wm/immersive_fullscreen_controller.h

Index: ash/wm/immersive_fullscreen_controller.h
diff --git a/ash/wm/immersive_fullscreen_controller.h b/ash/wm/immersive_fullscreen_controller.h
index 859b3fe9ecd8b57e5b7243d306734cb1732a79be..91364f93700d3afd25f38746d48d242aa66be3cc 100644
--- a/ash/wm/immersive_fullscreen_controller.h
+++ b/ash/wm/immersive_fullscreen_controller.h
@@ -190,6 +190,9 @@ class ASH_EXPORT ImmersiveFullscreenController
   // is a bezel sensor above the top container.
   bool ShouldHandleGestureEvent(const gfx::Point& location) const;
 
+  // Returns the display bounds of the screen |widget_| is on.
+  gfx::Rect GetDisplayBoundsInScreen() const;
+
   // Not owned.
   WmImmersiveFullscreenControllerDelegate* delegate_;
   views::View* top_container_;