Add optimized _OneByteString.toLowerCase.

sdk/lib/io/websocket_impl.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 const String _webSocketGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 
 // Matches _WebSocketOpcode.
 class _WebSocketMessageType {
@@ skipping 446 matching lines @@
 
   static bool _isUpgradeRequest(HttpRequest request) {
     if (request.method != "GET") {
       return false;
     }
     if (request.headers[HttpHeaders.CONNECTION] == null) {
       return false;
     }
     bool isUpgrade = false;
     request.headers[HttpHeaders.CONNECTION].forEach((String value) {
-      if (value.toLowerCase() == "upgrade") isUpgrade = true;
+      if (_ASCII.toLowerCase(value) == "upgrade") isUpgrade = true;
     });
     if (!isUpgrade) return false;
     String upgrade = request.headers.value(HttpHeaders.UPGRADE);
-    if (upgrade == null || upgrade.toLowerCase() != "websocket") {
+    if (upgrade == null || _ASCII.toLowerCase(upgrade) != "websocket") {
       return false;
     }
     String version = request.headers.value("Sec-WebSocket-Version");
     if (version == null || version != "13") {
       return false;
     }
     String key = request.headers.value("Sec-WebSocket-Key");
     if (key == null) {
       return false;
     }
@@ skipping 345 matching lines @@
         void error(String message) {
           // Flush data.
           response.detachSocket().then((socket) {
             socket.destroy();
           });
           throw new WebSocketException(message);
         }
         if (response.statusCode != HttpStatus.SWITCHING_PROTOCOLS ||
             response.headers[HttpHeaders.CONNECTION] == null ||
             !response.headers[HttpHeaders.CONNECTION].any(
-                (value) => value.toLowerCase() == "upgrade") ||
-            response.headers.value(HttpHeaders.UPGRADE).toLowerCase() !=
+                (value) => _ASCII.toLowerCase(value) == "upgrade") ||
+            _ASCII.toLowerCase(response.headers.value(HttpHeaders.UPGRADE)) !=
                 "websocket") {
           error("Connection to '$uri' was not upgraded to websocket");
         }
         String accept = response.headers.value("Sec-WebSocket-Accept");
         if (accept == null) {
           error("Response did not contain a 'Sec-WebSocket-Accept' header");
         }
         _SHA1 sha1 = new _SHA1();
         sha1.add("$nonce$_webSocketGUID".codeUnits);
         List<int> expectedAccept = sha1.close();
@@ skipping 136 matching lines @@
            (code < WebSocketStatus.NORMAL_CLOSURE ||
             code == WebSocketStatus.RESERVED_1004 ||
             code == WebSocketStatus.NO_STATUS_RECEIVED ||
             code == WebSocketStatus.ABNORMAL_CLOSURE ||
             (code > WebSocketStatus.INTERNAL_SERVER_ERROR &&
              code < WebSocketStatus.RESERVED_1015) ||
             (code >= WebSocketStatus.RESERVED_1015 &&
              code < 3000));
   }
 }