Make "--no-packages-dir" the default.

test/hosted/offline_test.dart

Index: test/hosted/offline_test.dart
diff --git a/test/hosted/offline_test.dart b/test/hosted/offline_test.dart
index 4be597a79068eccc3c22c547011cb92e493b9ec5..492045d32494a6c7ea75d1476379769c2554b376 100644
--- a/test/hosted/offline_test.dart
+++ b/test/hosted/offline_test.dart
@@ -31,7 +31,7 @@ main() {
 
       pubCommand(command, args: ['--offline'], warning: warning);
 
-      d.packagesDir({
+      d.appPackagesFile({
         "foo": "1.2.3",
         "bar": "1.2.3"
       }).validate();
@@ -57,7 +57,7 @@ main() {
 
       pubCommand(command, args: ['--offline'], warning: warning);
 
-      d.packagesDir({
+      d.appPackagesFile({
         "foo": "1.2.3-alpha.1"
       }).validate();
     });
@@ -120,7 +120,7 @@ main() {
 
       pubCommand(command, args: ['--offline']);
 
-      d.packagesDir({"foo": "1.2.3"}).validate();
+      d.appPackagesFile({"foo": "1.2.3"}).validate();
     });
   });
 }