Update listener error handling.

pkg/dart_parser/lib/src/error_kind.dart

Index: pkg/dart_parser/lib/src/error_kind.dart
diff --git a/pkg/dart_parser/lib/src/error_kind.dart b/pkg/dart_parser/lib/src/error_kind.dart
index 4fccfef49b5ba03baa860e5f1039ead97a23870b..f4df727e43e7e4a149c708e1dd68309c493858f0 100644
--- a/pkg/dart_parser/lib/src/error_kind.dart
+++ b/pkg/dart_parser/lib/src/error_kind.dart
@@ -5,27 +5,27 @@
 library dart_parser.error_kind;
 
 enum ErrorKind {
-  EMPTY_NAMED_PARAMETER_LIST,
-  EMPTY_OPTIONAL_PARAMETER_LIST,
-  EXPECTED_BODY,
-  EXPECTED_HEX_DIGIT,
-  EXPECTED_OPEN_PARENS,
-  EXPECTED_STRING,
-  EXTRANEOUS_MODIFIER,
-  EXTRANEOUS_MODIFIER_REPLACE,
-  INVALID_AWAIT_FOR,
-  INVALID_INPUT_CHARACTER,
-  INVALID_SYNC_MODIFIER,
-  INVALID_VOID,
-  MALFORMED_STRING_LITERAL,
-  MISSING_EXPONENT,
-  POSITIONAL_PARAMETER_WITH_EQUALS,
-  REQUIRED_PARAMETER_WITH_DEFAULT,
-  UNMATCHED_TOKEN,
-  UNSUPPORTED_PREFIX_PLUS,
-  UNTERMINATED_COMMENT,
-  UNTERMINATED_STRING,
-  UNTERMINATED_TOKEN,
+  EmptyNamedParameterList,
+  EmptyOptionalParameterList,
+  ExpectedBody,
+  ExpectedHexDigit,
+  ExpectedOpenParens,
+  ExpectedString,
+  ExtraneousModifier,
+  ExtraneousModifierReplace,
+  InvalidAwaitFor,
+  InvalidInputCharacter,
+  InvalidSyncModifier,
+  InvalidVoid,
+  MalformedStringLiteral,
+  MissingExponent,
+  PositionalParameterWithEquals,
+  RequiredParameterWithDefault,
+  UnmatchedToken,
+  UnsupportedPrefixPlus,
+  UnterminatedComment,
+  UnterminatedString,
+  UnterminatedToken,
 
-  UNSPECIFIED,
+  Unspecified,
 }