mash: Use mojo for ShelfItemDelegate and [app] MenuItem.

ash/common/shelf/shelf_model.cc

Index: ash/common/shelf/shelf_model.cc
diff --git a/ash/common/shelf/shelf_model.cc b/ash/common/shelf/shelf_model.cc
index a68447588ef940cf69fbaea5d4fdcd7b25dacd86..88875b2f43da0abcd25b8b155e26ec651bc1c622 100644
--- a/ash/common/shelf/shelf_model.cc
+++ b/ash/common/shelf/shelf_model.cc
@@ -6,7 +6,6 @@
 
 #include <algorithm>
 
-#include "ash/common/shelf/shelf_item_delegate.h"
 #include "ash/common/shelf/shelf_model_observer.h"
 
 namespace ash {
@@ -159,7 +158,7 @@ int ShelfModel::FirstPanelIndex() const {
 
 void ShelfModel::SetShelfItemDelegate(
     ShelfID id,
-    std::unique_ptr<ShelfItemDelegate> item_delegate) {
+    std::unique_ptr<mojom::ShelfItemDelegate> item_delegate) {
   // If another ShelfItemDelegate is already registered for |id|, we assume
   // that this request is replacing ShelfItemDelegate for |id| with
   // |item_delegate|.
@@ -171,7 +170,7 @@ void ShelfModel::SetShelfItemDelegate(
   id_to_item_delegate_map_[id] = std::move(item_delegate);
 }
 
-ShelfItemDelegate* ShelfModel::GetShelfItemDelegate(ShelfID id) {
+mojom::ShelfItemDelegate* ShelfModel::GetShelfItemDelegate(ShelfID id) {
   if (id_to_item_delegate_map_.find(id) != id_to_item_delegate_map_.end())
     return id_to_item_delegate_map_[id].get();
   return nullptr;