Remove LauncherItemController::Launch, cleanup.

chrome/browser/ui/ash/launcher/chrome_launcher_controller_mus.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/ash/launcher/chrome_launcher_controller_mus.h"
 
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
@@ skipping 16 matching lines @@
       mojo::AssociatedGroup* associated_group) {
     DCHECK(!item_delegate_binding_.is_bound());
     ash::mojom::ShelfItemDelegateAssociatedPtrInfo ptr_info;
     item_delegate_binding_.Bind(&ptr_info, associated_group);
     return ptr_info;
   }
 
  private:
   // ash::mojom::ShelfItemDelegate:
   void LaunchItem() override {
-    controller_->LaunchApp(app_id_, ash::LAUNCH_FROM_UNKNOWN, ui::EF_NONE);
+    controller_->LaunchApp(app_id_, std::string(), ash::LAUNCH_FROM_UNKNOWN,
+                           ui::EF_NONE);
   }
   void ExecuteCommand(uint32_t command_id, int32_t event_flags) override {
     NOTIMPLEMENTED();
   }
   void ItemPinned() override { NOTIMPLEMENTED(); }
   void ItemUnpinned() override { NOTIMPLEMENTED(); }
   void ItemReordered(uint32_t order) override { NOTIMPLEMENTED(); }
 
   std::string app_id_;
   mojo::AssociatedBinding<ash::mojom::ShelfItemDelegate> item_delegate_binding_;
@@ skipping 249 matching lines @@
     app_id_to_item_delegate_.insert(
         std::make_pair(app_id, std::move(delegate)));
 
     AppIconLoader* app_icon_loader = GetAppIconLoaderForApp(app_id);
     if (app_icon_loader) {
       app_icon_loader->FetchImage(app_id);
       app_icon_loader->UpdateImage(app_id);
     }
   }
 }