mash: Remove ShelfDelegate; move functions to ShelfModel.

ash/shelf/shelf_model.h

Index: ash/shelf/shelf_model.h
diff --git a/ash/shelf/shelf_model.h b/ash/shelf/shelf_model.h
index b3bb09eb077cfb3298fbb2f0b3e09c9404103794..68bb326e2c788972be2c5daae88e19f96d42806f 100644
--- a/ash/shelf/shelf_model.h
+++ b/ash/shelf/shelf_model.h
@@ -9,6 +9,7 @@
 #include <memory>
 
 #include "ash/ash_export.h"
+#include "ash/public/cpp/app_launch_id.h"
 #include "ash/public/cpp/shelf_item.h"
 #include "ash/public/interfaces/shelf.mojom.h"
 #include "base/macros.h"
@@ -25,6 +26,35 @@ class ASH_EXPORT ShelfModel {
   ShelfModel();
   ~ShelfModel();
 
+  // Get the shelf ID from an application ID. Returns kInvalidShelfID if the
+  // app id is unknown, or has no associated ShelfID.
+  ShelfID GetShelfIDForAppID(const std::string& app_id);
+
+  // Get the shelf ID from an application ID and a launch ID.
+  // The launch ID can be passed to an app when launched in order to support
+  // multiple shelf items per app. This id is used together with the app_id to
+  // uniquely identify each shelf item that has the same app_id.
+  // For example, a single virtualization app might want to show different
+  // shelf icons for different remote apps. Returns kInvalidShelfID if the app
+  // id is unknown or has no associated ShelfID.
+  ShelfID GetShelfIDForAppIDAndLaunchID(const std::string& app_id,
+                                        const std::string& launch_id);
+
+  // Get the application ID for a given shelf ID. Returns an empty string for
+  // an unknown or invalid ShelfID.
+  const std::string& GetAppIDForShelfID(ShelfID id);
+
+  // Pins an app with |app_id| to shelf. A running instance will get pinned.
+  // In case there is no running instance a new shelf item is created and
+  // pinned.
+  void PinAppWithID(const std::string& app_id);
+
+  // Check if the app with |app_id_| is pinned to the shelf.
+  bool IsAppPinned(const std::string& app_id);
+
+  // Unpins app item with |app_id|.
+  void UnpinAppWithID(const std::string& app_id);
+
   // Cleans up the ShelfItemDelegates.
   void DestroyItemDelegates();