Remove tests of a workaround that no longer exists 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 b800b0cf4b48feb5584c4bd4716f2b846cdf1529..1205d74840b826c463aaa4decd3fb14fd2486022 100644
--- a/pkg/stack_trace/test/frame_test.dart
+++ b/pkg/stack_trace/test/frame_test.dart
@@ -30,33 +30,6 @@ 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:io/timer_impl.dart")));
-      expect(frame.line, equals(24));
-      expect(frame.column, null);
-      expect(frame.member, equals('Foo._bar'));
-    });
-
-    test('parses a stack frame with http_parser correctly', () {
-      var frame = new Frame.parseVM("#1      Foo._bar "
-          "(http_parser.dart:24)");
-      expect(frame.uri, equals(Uri.parse("dart:io/http_parser.dart")));
-      expect(frame.line, equals(24));
-      expect(frame.column, null);
-      expect(frame.member, equals('Foo._bar'));
-    });
-
-    test('parses a stack frame with http_impl correctly', () {
-      var frame = new Frame.parseVM("#1      Foo._bar "
-          "(http_impl.dart:24)");
-      expect(frame.uri, equals(Uri.parse("dart:io/http_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;