fasta.CommentToken implement analyzer.CommentToken

pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart

Index: pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart
diff --git a/pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart b/pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart
index 291ddf3290fdea1adcc69aa0b942267260a64f30..de8964b5c883641ecc8510c87882c68be085c515 100644
--- a/pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart
+++ b/pkg/front_end/lib/src/fasta/scanner/utf8_bytes_scanner.dart
@@ -10,7 +10,7 @@ import '../scanner.dart' show unicodeReplacementCharacter;
 
 import 'precedence.dart' show PrecedenceInfo;
 
-import 'token.dart' show StringToken;
+import 'token.dart' show CommentToken, DartDocToken, StringToken;
 
 import 'array_based_scanner.dart' show ArrayBasedScanner;
 
@@ -203,5 +203,21 @@ class Utf8BytesScanner extends ArrayBasedScanner {
         info, bytes, start, byteOffset + extraOffset, asciiOnly, tokenStart);
   }
 
+  @override
+  CommentToken createCommentToken(
+      PrecedenceInfo info, int start, bool asciiOnly,
+      [int extraOffset = 0]) {
+    return new CommentToken.fromUtf8Bytes(
+        info, bytes, start, byteOffset + extraOffset, asciiOnly, tokenStart);
+  }
+
+  @override
+  DartDocToken createDartDocToken(
+      PrecedenceInfo info, int start, bool asciiOnly,
+      [int extraOffset = 0]) {
+    return new DartDocToken.fromUtf8Bytes(
+        info, bytes, start, byteOffset + extraOffset, asciiOnly, tokenStart);
+  }
+
   bool atEndOfFile() => byteOffset >= bytes.length - 1;
 }