mash: Disable ash_sysui; begin removal.

ash/sysui/public/interfaces/wallpaper.mojom

Index: ash/sysui/public/interfaces/wallpaper.mojom
diff --git a/ash/sysui/public/interfaces/wallpaper.mojom b/ash/sysui/public/interfaces/wallpaper.mojom
deleted file mode 100644
index af7b7128db1f31169005e373858f9db7767d15b1..0000000000000000000000000000000000000000
--- a/ash/sysui/public/interfaces/wallpaper.mojom
+++ /dev/null
@@ -1,20 +0,0 @@
-// 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.
-
-module ash.sysui.mojom;
-
-import "skia/public/interfaces/bitmap.mojom";
-
-// These values match wallpaper::WallpaperLayout.
-enum WallpaperLayout { CENTER, CENTER_CROPPED, STRETCH, TILE, };
-
-// Used by Chrome to set the wallpaper displayed by ash_sysui.
-interface WallpaperController {
-  SetWallpaper(skia.mojom.Bitmap wallpaper, WallpaperLayout layout);
-};
-
-// Used by ash_sysui to trigger Chrome's wallpaper picker functionality.
-interface WallpaperManager {
-  Open();
-};