Add support for client-side GZip compression.

sdk/lib/io/http_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;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
   final Completer _dataCompleter = new Completer();
   Stream<List<int>> _stream;
@@ skipping 216 matching lines @@
                                                            method,
                                                            url));
           return request.close();
         });
   }
 
   StreamSubscription<List<int>> listen(void onData(List<int> event),
                                        {void onError(AsyncError error),
                                         void onDone(),
                                         bool unsubscribeOnError}) {
-    return _incoming.listen(onData,
-                            onError: onError,
-                            onDone: onDone,
-                            unsubscribeOnError: unsubscribeOnError);
+    var stream = _incoming;
+    if (headers.value(HttpHeaders.CONTENT_ENCODING) == "gzip") {
+      stream = stream.transform(new ZLibInflater());
+    }
+    return stream.listen(onData,
+                         onError: onError,
+                         onDone: onDone,
+                         unsubscribeOnError: unsubscribeOnError);
   }
 
   Future<Socket> detachSocket() {
     _httpClient._connectionClosed(_httpRequest._httpClientConnection);
     return _httpRequest._httpClientConnection.detachSocket();
   }
 
   HttpConnectionInfo get connectionInfo => _httpRequest.connectionInfo;
 
   bool get _shouldAuthenticate {
@@ skipping 713 matching lines @@
     var outgoing = new _HttpOutgoing();
     // Create new request object, wrapping the outgoing connection.
     var request = new _HttpClientRequest(outgoing,
                                          uri,
                                          method,
                                          !isDirect,
                                          _httpClient,
                                          this);
     request.headers.host = uri.domain;
     request.headers.port = port;
+    request.headers.set(HttpHeaders.ACCEPT_ENCODING, "gzip");
     if (uri.userInfo != null && !uri.userInfo.isEmpty) {
       // If the URL contains user information use that for basic
       // authorization
       String auth =
           CryptoUtils.bytesToBase64(_encodeString(uri.userInfo));
       request.headers.set(HttpHeaders.AUTHORIZATION, "Basic $auth");
     } else {
       // Look for credentials.
       _Credentials cr = _httpClient._findCredentials(uri);
       if (cr != null) {
@@ skipping 820 matching lines @@
 
 
 class _RedirectInfo implements RedirectInfo {
   const _RedirectInfo(int this.statusCode,
                       String this.method,
                       Uri this.location);
   final int statusCode;
   final String method;
   final Uri location;
 }