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

ash/common/shelf/shelf_widget.cc

Index: ash/common/shelf/shelf_widget.cc
diff --git a/ash/common/shelf/shelf_widget.cc b/ash/common/shelf/shelf_widget.cc
index d735e5897c17a0ddbd815142ed7698def34e053b..e80b8bf997f3d9c59a9f5e7e0ff9dd532c621755 100644
--- a/ash/common/shelf/shelf_widget.cc
+++ b/ash/common/shelf/shelf_widget.cc
@@ -331,12 +331,6 @@
   // Ensure the newly created |shelf_| gets current values.
   background_animator_.Initialize(this);
 
-  // TODO(jamescook): The IsActiveUserSessionStarted() check may not be needed
-  // because the shelf is only created after the first user session is active.
-  // The ShelfView seems to always be visible after login. At the lock screen
-  // the shelf is hidden because its container is hidden. During auto-hide it is
-  // hidden because ShelfWidget is transparent. Some of the ShelfView visibility
-  // code could be simplified. http://crbug.com/674773
   shelf_view_->SetVisible(
       WmShell::Get()->GetSessionStateDelegate()->IsActiveUserSessionStarted());
   shelf_layout_manager_->LayoutShelf();
@@ -346,6 +340,11 @@
 
 bool ShelfWidget::IsShelfVisible() const {
   return shelf_view_ && shelf_view_->visible();
+}
+
+void ShelfWidget::SetShelfVisibility(bool visible) {
+  if (shelf_view_)
+    shelf_view_->SetVisible(visible);
 }
 
 bool ShelfWidget::IsShowingAppList() const {
@@ -389,9 +388,6 @@
 }
 
 void ShelfWidget::UpdateIconPositionForPanel(WmWindow* panel) {
-  if (!shelf_view_)
-    return;
-
   WmWindow* shelf_window = WmLookup::Get()->GetWindowForWidget(this);
   shelf_view_->UpdatePanelIconPosition(
       panel->GetIntProperty(WmWindowProperty::SHELF_ID),
@@ -400,11 +396,6 @@
 }
 
 gfx::Rect ShelfWidget::GetScreenBoundsOfItemIconForWindow(WmWindow* window) {
-  // Window animations can be triggered during session restore before the shelf
-  // view is created. In that case, return default empty bounds.
-  if (!shelf_view_)
-    return gfx::Rect();
-
   ShelfID id = window->GetIntProperty(WmWindowProperty::SHELF_ID);
   gfx::Rect bounds(shelf_view_->GetIdealBoundsOfItemIcon(id));
   gfx::Point screen_origin;