ash: Remove unnecessary utility methods from ash::Shelf

ash/shelf/shelf.cc

Index: ash/shelf/shelf.cc
diff --git a/ash/shelf/shelf.cc b/ash/shelf/shelf.cc
index 071a57bc6e393b9d563cddceb65a8c7e20da00ed..239fe40623655aae2e3a85378d9bf7b7f3860713 100644
--- a/ash/shelf/shelf.cc
+++ b/ash/shelf/shelf.cc
@@ -136,18 +136,6 @@ void Shelf::CycleWindowLinear(CycleDirection direction) {
     ActivateShelfItem(item_index);
 }
 
-bool Shelf::IsShowingMenu() const {
-  return shelf_view_->IsShowingMenu();
-}
-
-bool Shelf::IsShowingOverflowBubble() const {
-  return shelf_view_->IsShowingOverflowBubble();
-}
-
-bool Shelf::IsVisible() const {
-  return shelf_view_->visible();
-}
-
 AppListButton* Shelf::GetAppListButton() const {
   return shelf_view_->GetAppListButton();
 }