Work around issue 7218 in Pub.

utils/tests/pub/test_pub.dart

Index: utils/tests/pub/test_pub.dart
diff --git a/utils/tests/pub/test_pub.dart b/utils/tests/pub/test_pub.dart
index 846a21514b049b433b1ca1fccad0904f60516a6e..18338316de78123a3db38630ef5a7b8cf7d9b1dd 100644
--- a/utils/tests/pub/test_pub.dart
+++ b/utils/tests/pub/test_pub.dart
@@ -1334,8 +1334,8 @@ class ScheduledProcess {
   /// Wraps a [Process] [Future] in a scheduled process.
   ScheduledProcess(this.name, Future<Process> process)
     : _process = process,
-      _stdout = process.transform((p) => _wrapStream(p.stdout)),
-      _stderr = process.transform((p) => _wrapStream(p.stderr)) {
+      _stdout = process.transform((p) => new StringInputStream(p.stdout)),
+      _stderr = process.transform((p) => new StringInputStream(p.stderr)) {
 
     _schedule((_) {
       if (!_endScheduled) {
@@ -1466,12 +1466,6 @@ class ScheduledProcess {
     });
   }
 
-  /// Wraps [source] and ensures it gets eagerly drained. We do this to make
-  /// sure a process will exit even if we don't care about its output.
-  static StringInputStream _wrapStream(InputStream source) {
-    return new StringInputStream(wrapInputStream(source));
-  }
-
   /// Prints the remaining data in the process's stdout and stderr streams.
   /// Prints nothing if the straems are empty.
   Future _printStreams() {