Work around issue 11901 in stack_trace.

pkg/stack_trace/test/frame_test.dart

Index: pkg/stack_trace/test/frame_test.dart
diff --git a/pkg/stack_trace/test/frame_test.dart b/pkg/stack_trace/test/frame_test.dart
index 87a8c4dc777c90db098f45d75e82516f15a6c08c..bd09ed882e35f8b487b02bfb46bce336762c00a2 100644
--- a/pkg/stack_trace/test/frame_test.dart
+++ b/pkg/stack_trace/test/frame_test.dart
@@ -30,6 +30,15 @@ void main() {
       expect(frame.member, equals('Foo._bar'));
     });
 
+    test('parses a stack frame with timer_impl correctly', () {
+      var frame = new Frame.parseVM("#1      Foo._bar "
+          "(timer_impl.dart:24)");
+      expect(frame.uri, equals(Uri.parse("dart:async/timer_impl.dart")));
+      expect(frame.line, equals(24));
+      expect(frame.column, null);
+      expect(frame.member, equals('Foo._bar'));
+    });
+
     test('converts "<anonymous closure>" to "<fn>"', () {
       String parsedMember(String member) =>
           new Frame.parseVM('#0 $member (foo:0:0)').member;