aura-mus: create an interactive ui test for drag and drop.

ui/views/mus/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//services/catalog/public/tools/catalog.gni")
 import("//services/service_manager/public/cpp/service.gni")
 import("//services/service_manager/public/service_manifest.gni")
 import("//testing/test.gni")
@@ skipping 210 matching lines @@
 }
 
 # Tests that must run sequentially because they access system-wide features
 # like capture.
 test("views_mus_interactive_ui_tests") {
   testonly = true
 
   sources = [
     "../widget/widget_interactive_uitest.cc",
     "clipboard_unittest.cc",
+    "drag_interactive_uitest.cc",
     "interactive_ui_tests_mus.cc",
   ]
 
   deps = [
     ":mus",
     ":test_support",
     "//base",
     "//testing/gmock",
     "//testing/gtest",
     "//ui/aura",
+    "//ui/aura:test_support",
     "//ui/base",
     "//ui/base/ime",
     "//ui/events:events_base",
     "//ui/events:test_support",
     "//ui/gl:test_support",
     "//ui/touch_selection",
     "//ui/views",
     "//ui/views:test_support_internal",
     "//ui/wm",
   ]
@@ skipping 43 matching lines @@
 copy("views_mus_tests_catalog_copy") {
   testonly = true
   sources = get_target_outputs(":views_mus_tests_catalog")
   outputs = [
     "${root_out_dir}/views_mus_tests_catalog.json",
   ]
   deps = [
     ":views_mus_tests_catalog",
   ]
 }