Make servePackages's contents argument saner.

sdk/lib/_internal/pub/test/snapshot/doesnt_snapshot_an_entrypoint_dependency_test.dart

Index: sdk/lib/_internal/pub/test/snapshot/doesnt_snapshot_an_entrypoint_dependency_test.dart
diff --git a/sdk/lib/_internal/pub/test/snapshot/doesnt_snapshot_an_entrypoint_dependency_test.dart b/sdk/lib/_internal/pub/test/snapshot/doesnt_snapshot_an_entrypoint_dependency_test.dart
index 164344ced0a00874ba81870fc6e931a269ecbc59..35a6872cb1ae6e0f52f0ff845a30e313c017a16a 100644
--- a/sdk/lib/_internal/pub/test/snapshot/doesnt_snapshot_an_entrypoint_dependency_test.dart
+++ b/sdk/lib/_internal/pub/test/snapshot/doesnt_snapshot_an_entrypoint_dependency_test.dart
@@ -14,12 +14,16 @@ main() {
   initConfig();
   integration("doesn't create a snapshot for a package that depends on the "
       "entrypoint", () {
-    servePackages([
-      packageMap("foo", "1.2.3", {'bar': '1.2.3'}),
-      packageMap("bar", "1.2.3", {'myapp': 'any'})
-    ], contents: [
-      d.dir("bin", [d.file("hello.dart", "void main() => print('hello!');")])
-    ]);
+    servePackages((builder) {
+      builder.serve("foo", "1.2.3", pubspec: {
+        "dependencies": {'bar': '1.2.3'}
+      }, contents: [
+        d.dir("bin", [d.file("hello.dart", "void main() => print('hello!');")])
+      ]);
+      builder.serve("bar", "1.2.3", pubspec: {
+        "dependencies": {'myapp': 'any'}
+      });
+    });
 
     d.appDir({"foo": "1.2.3"}).create();