mash: Port mojo:ash_sysui's ContextMenuMus to mojo:ash.

chrome/browser/ui/ash/chrome_shell_delegate.h

Index: chrome/browser/ui/ash/chrome_shell_delegate.h
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate.h b/chrome/browser/ui/ash/chrome_shell_delegate.h
index 50f716dfbeecb22a489d849c3f605c1d651db10f..707ee6ede698c536bad4fd07a57bbfcd34069385 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.h
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.h
@@ -46,7 +46,7 @@ class ChromeShellDelegate : public ash::ShellDelegate,
   app_list::AppListPresenter* GetAppListPresenter() override;
   ash::ShelfDelegate* CreateShelfDelegate(ash::ShelfModel* model) override;
   ash::SystemTrayDelegate* CreateSystemTrayDelegate() override;
-  ash::UserWallpaperDelegate* CreateUserWallpaperDelegate() override;
+  ash::WallpaperDelegate* CreateWallpaperDelegate() override;
   ash::SessionStateDelegate* CreateSessionStateDelegate() override;
   ash::AccessibilityDelegate* CreateAccessibilityDelegate() override;
   ash::NewWindowDelegate* CreateNewWindowDelegate() override;