Remove unused API.

dart/sdk/lib/_internal/compiler/implementation/string_validator.dart

 // Copyright (c) 2012, 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.
 
 // Check the validity of string literals.
 
 library stringvalidator;
 
 import "dart:collection";
 
 import "dart2jslib.dart";
 import "tree/tree.dart";
 import "util/characters.dart";
 import "scanner/scannerlib.dart" show Token;
 
 class StringValidator {
   final DiagnosticListener listener;
 
   StringValidator(this.listener);
 
-  DartString validateQuotedString(Token token) {
-    String source = token.value;
-    StringQuoting quoting = quotingFromString(source);
-    int leftQuote = quoting.leftQuoteLength;
-    int rightQuote = quoting.rightQuoteLength;
-    String content = copyWithoutQuotes(source, leftQuote, rightQuote);
-    return validateString(token,
-                          token.charOffset + leftQuote,
-                          content,
-                          quoting);
-  }
-
   DartString validateInterpolationPart(Token token, StringQuoting quoting,
                                        {bool isFirst: false,
                                         bool isLast: false}) {
     String source = token.value;
     int leftQuote = 0;
     int rightQuote = 0;
     if (isFirst) leftQuote = quoting.leftQuoteLength;
     if (isLast) rightQuote = quoting.rightQuoteLength;
     String content = copyWithoutQuotes(source, leftQuote, rightQuote);
     return validateString(token,
@@ skipping 174 matching lines @@
       return null;
     }
     // String literal successfully validated.
     if (quoting.raw || !containsEscape) {
       // A string without escapes could just as well have been raw.
       return new DartString.rawString(string, length);
     }
     return new DartString.escapedString(string, length);
   }
 }