Remove support for the special "assets" directory.

sdk/lib/_internal/pub/test/serve/warns_on_serve_from_asset_test.dart

Index: sdk/lib/_internal/pub/test/serve/warns_on_serve_from_asset_test.dart
diff --git a/sdk/lib/_internal/pub/test/serve/warns_on_serve_from_asset_test.dart b/sdk/lib/_internal/pub/test/serve/warns_on_serve_from_asset_test.dart
deleted file mode 100644
index 2f4fc497cbccd8a95ad10a801745162073c7f3a5..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub/test/serve/warns_on_serve_from_asset_test.dart
+++ /dev/null
@@ -1,56 +0,0 @@
-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library pub_tests;
-
-import 'package:scheduled_test/scheduled_stream.dart';
-
-import '../descriptor.dart' as d;
-import '../test_pub.dart';
-import 'utils.dart';
-
-main() {
-  initConfig();
-  integration("warns if an asset from the entrypoint package's 'asset' "
-      "directory is requested", () {
-    d.dir(appPath, [
-      d.appPubspec(),
-      d.dir("asset", [
-        d.file("file.txt", "body")
-      ])
-    ]).create();
-
-    var pub = pubServe();
-    requestShouldSucceed("assets/myapp/file.txt", "body");
-
-    pub.stderr.expect(consumeThrough(emitsLines('''
-Warning: Support for the "asset" directory is deprecated and will be removed soon.
-Please move "asset/file.txt" to "lib/file.txt".''')));
-    endPubServe();
-  });
-
-  integration("warns if an asset from a dependency's 'asset' directory is "
-      "requested", () {
-    d.dir("foo", [
-      d.libPubspec("foo", "0.0.1"),
-      d.dir("asset", [
-        d.file("file.txt", "body")
-      ])
-    ]).create();
-
-    d.dir(appPath, [
-      d.appPubspec({
-        "foo": {"path": "../foo"}
-      })
-    ]).create();
-
-    var pub = pubServe(shouldGetFirst: true);
-    requestShouldSucceed("assets/foo/file.txt", "body");
-
-    pub.stderr.expect(consumeThrough(emitsLines('''
-Warning: Support for the "asset" directory is deprecated and will be removed soon.
-Please ask the maintainer of "foo" to move "asset/file.txt" to "lib/file.txt".''')));
-    endPubServe();
-  });
-}