Make servePackages's contents argument saner.

sdk/lib/_internal/pub/test/global/run/runs_script_test.dart

Index: sdk/lib/_internal/pub/test/global/run/runs_script_test.dart
diff --git a/sdk/lib/_internal/pub/test/global/run/runs_script_test.dart b/sdk/lib/_internal/pub/test/global/run/runs_script_test.dart
index caf8f42d0e6637bc708dd6681b3cb62835995e67..fb13d4371ce8b60f0c55715eabedc8651aff8703 100644
--- a/sdk/lib/_internal/pub/test/global/run/runs_script_test.dart
+++ b/sdk/lib/_internal/pub/test/global/run/runs_script_test.dart
@@ -10,11 +10,13 @@ main() {
   integration('runs a script in an activated package', () {
     servePackages([
       packageMap("foo", "1.0.0")
-    ], contents: [
-      d.dir("bin", [
-        d.file("script.dart", "main(args) => print('ok');")
-      ])
-    ]);
+    ], contents: {
+      'foo-1.0.0': [
+        d.dir("bin", [
+          d.file("script.dart", "main(args) => print('ok');")
+        ])
+      ]
+    });
 
     schedulePub(args: ["global", "activate", "foo"]);