remove fasta <--> analyzer token translation

pkg/front_end/test/scanner_roundtrip_test.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analyzer/src/fasta/token_utils.dart';
 import 'package:front_end/src/scanner/errors.dart' as analyzer;
 import 'package:front_end/src/scanner/reader.dart' as analyzer;
 import 'package:front_end/src/scanner/scanner.dart' as analyzer;
 import 'package:front_end/src/scanner/token.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'scanner_fasta_test.dart';
 import 'scanner_test.dart';
 
 main() {
-  defineReflectiveSuite(() {
-    defineReflectiveTests(ScannerTest_RoundTrip);
-  });
-}
-
-/// Scanner tests that use the analyzer scanner, then convert the resulting
-/// token stream into a Fasta token stream, then convert back to an analyzer
-/// token stream before verifying assertions.
-///
-/// These tests help to validate the correctness of the analyzer->Fasta token
-/// stream conversion.
-@reflectiveTest
-class ScannerTest_RoundTrip extends ScannerTest {
-  @override
-  Token scanWithListener(String source, ErrorListener listener,
-      {bool genericMethodComments: false,
-      bool lazyAssignmentOperators: false}) {
-    var analyzerToken = super.scanWithListener(source, listener,
-        genericMethodComments: genericMethodComments,
-        lazyAssignmentOperators: lazyAssignmentOperators);
-    var fastaToken = fromAnalyzerTokenStream(analyzerToken);
-    // Since [scanWithListener] reports errors to the listener, we don't
-    // expect any error tokens in the Fasta token stream, so we convert using
-    // ToAnalyzerTokenStreamConverter_NoErrors.
-    return new ToAnalyzerTokenStreamConverter_NoErrors()
-        .convertTokens(fastaToken);
-  }
+  // round trip test removed

[ahe, 2017/05/24 21:32:00]

Shouldn't you just delete this file?

[danrubel, 2017/05/25 01:08:15]

Good point. Done.
https://codereview.chromium.org/2900303003/

 }
 
 class TestScanner extends analyzer.Scanner {
   TestScanner(analyzer.CharacterReader reader) : super.create(reader);
 
   @override
   void reportError(
       analyzer.ScannerErrorCode errorCode, int offset, List<Object> arguments) {
     fail('Unexpected error $errorCode while scanning offset $offset\n'
         '   arguments: $arguments');
   }
 }