Enable immersive fullscreen on Windows Ash.

ash/wm/custom_frame_view_ash.cc

Index: ash/wm/custom_frame_view_ash.cc
diff --git a/ash/wm/custom_frame_view_ash.cc b/ash/wm/custom_frame_view_ash.cc
index 4eb5c8fb20699cfc2bfdecc66e458dc038645d8c..3c244e91613cbb2694db5fa6462fcca5220262e6 100644
--- a/ash/wm/custom_frame_view_ash.cc
+++ b/ash/wm/custom_frame_view_ash.cc
@@ -55,9 +55,6 @@ class CustomFrameViewAshWindowStateDelegate
       ash::wm::WindowState* window_state,
       ash::CustomFrameViewAsh* custom_frame_view)
       : window_state_(NULL) {
-#if defined(OS_CHROMEOS)
-    // TODO(pkotwicz): Investigate if immersive fullscreen can be enabled for
-    // Windows Ash.
     if (ash::switches::UseImmersiveFullscreenForAllWindows()) {
       immersive_fullscreen_controller_.reset(
           new ash::ImmersiveFullscreenController);
@@ -73,7 +70,6 @@ class CustomFrameViewAshWindowStateDelegate
       window_state_->AddObserver(this);
       window_state_->window()->AddObserver(this);
     }
-#endif
   }
   virtual ~CustomFrameViewAshWindowStateDelegate() {
     if (window_state_) {