Remove support for the special "assets" directory.

sdk/lib/_internal/pub/test/transformer/runs_a_transformer_on_a_dependency_test.dart

Index: sdk/lib/_internal/pub/test/transformer/runs_a_transformer_on_a_dependency_test.dart
diff --git a/sdk/lib/_internal/pub/test/transformer/runs_a_transform_on_a_dependency_test.dart b/sdk/lib/_internal/pub/test/transformer/runs_a_transformer_on_a_dependency_test.dart
similarity index 79%
rename from sdk/lib/_internal/pub/test/transformer/runs_a_transform_on_a_dependency_test.dart
rename to sdk/lib/_internal/pub/test/transformer/runs_a_transformer_on_a_dependency_test.dart
index bf7f772119a771ba3674cde348bc727bb77eb0d0..b2092e557d86537c249158f4d2b6076ed6c5b5ee 100644
--- a/sdk/lib/_internal/pub/test/transformer/runs_a_transform_on_a_dependency_test.dart
+++ b/sdk/lib/_internal/pub/test/transformer/runs_a_transformer_on_a_dependency_test.dart
@@ -11,7 +11,7 @@ import '../serve/utils.dart';
 main() {
   initConfig();
   withBarbackVersions("any", () {
-    integration("runs a local transform on a dependency", () {
+    integration("runs a local transformer on a dependency", () {
       d.dir("foo", [
         d.pubspec({
           "name": "foo",
@@ -19,9 +19,7 @@ main() {
           "transformers": ["foo/transformer"]
         }),
         d.dir("lib", [
-          d.file("transformer.dart", REWRITE_TRANSFORMER)
-        ]),
-        d.dir("asset", [
+          d.file("transformer.dart", REWRITE_TRANSFORMER),
           d.file("foo.txt", "foo")
         ])
       ]).create();
@@ -33,7 +31,7 @@ main() {
       createLockFile('myapp', sandbox: ['foo'], pkg: ['barback']);
 
       pubServe();
-      requestShouldSucceed("assets/foo/foo.out", "foo.out");
+      requestShouldSucceed("packages/foo/foo.out", "foo.out");
       endPubServe();
     });
   });