Fix recursive directory-deletion of top-level files/links.

utils/pub/io.dart

Index: utils/pub/io.dart
diff --git a/utils/pub/io.dart b/utils/pub/io.dart
index 3eed22c0aa971b3a7e3c35dc7221df5348ebe2f2..0b6445b3d799470dd2ae780f4fa59bbd099e81ee 100644
--- a/utils/pub/io.dart
+++ b/utils/pub/io.dart
@@ -188,12 +188,7 @@ bool dirExists(String dir) => new Directory(dir).existsSync();
 void deleteEntry(String path) {
   if (linkExists(path)) {
     log.io("Deleting link $path.");
-    if (Platform.operatingSystem == 'windows') {
-      // TODO(nweiz): remove this when issue 9278 is fixed.
-      new Directory(path).deleteSync();
-    } else {
-      new Link(path).deleteSync();
-    }
+    new Link(path).deleteSync();
   } else if (dirExists(path)) {
     log.io("Deleting directory $path.");
     new Directory(path).deleteSync(recursive: true);