Revert of Reland: chromeos: Fix shelf appearing at login screen under mash

ash/common/wm_root_window_controller.cc

Index: ash/common/wm_root_window_controller.cc
diff --git a/ash/common/wm_root_window_controller.cc b/ash/common/wm_root_window_controller.cc
index 06ab6f220e5609a9ad1c5c070acc53fc5c474229..35767001cb64d8c275996d988de5fe5d05433f4c 100644
--- a/ash/common/wm_root_window_controller.cc
+++ b/ash/common/wm_root_window_controller.cc
@@ -248,6 +248,14 @@
   wm_shelf_->shelf_widget()->PostCreateShelf();
 }
 
+void RootWindowController::ShowShelf() {
+  if (!wm_shelf_->IsShelfInitialized())
+    return;
+  // TODO(jamescook): Move this into WmShelf.
+  wm_shelf_->shelf_widget()->SetShelfVisibility(true);
+  wm_shelf_->shelf_widget()->status_area_widget()->Show();
+}
+
 const WmWindow* RootWindowController::GetWindow() const {
   return WmWindowAura::Get(GetRootWindow());
 }