Add HttpServer:autoCompress option, to disable auto 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;
 
 const int _OUTGOING_BUFFER_SIZE = 8 * 1024;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
@@ skipping 930 matching lines @@
             " bytes"));
       }
     }
     if (headersWritten) return null;
     headersWritten = true;
     Future drainFuture;
     bool isServerSide = outbound is _HttpResponse;
     bool gzip = false;
     if (isServerSide) {
       var response = outbound;
-      if (outbound.bufferOutput && outbound.headers.chunkedTransferEncoding) {
+      if (response._httpRequest._httpServer.autoCompress &&
+          outbound.bufferOutput &&
+          outbound.headers.chunkedTransferEncoding) {
         List acceptEncodings =
             response._httpRequest.headers[HttpHeaders.ACCEPT_ENCODING];
         List contentEncoding = outbound.headers[HttpHeaders.CONTENT_ENCODING];
         if (acceptEncodings != null &&
             acceptEncodings
                 .expand((list) => list.split(","))
                 .any((encoding) => encoding.trim().toLowerCase() == "gzip") &&
             contentEncoding == null) {
           outbound.headers.set(HttpHeaders.CONTENT_ENCODING, "gzip");
           gzip = true;
@@ skipping 1181 matching lines @@
 
 // HTTP server waiting for socket connections.
 class _HttpServer
     extends Stream<HttpRequest> with _ServiceObject
     implements HttpServer {
   // Use default Map so we keep order.
   static Map<int, _HttpServer> _servers = new Map<int, _HttpServer>();
 
   String serverHeader;
   final HttpHeaders defaultResponseHeaders = _initDefaultResponseHeaders();
+  bool autoCompress = true;
 
   Duration _idleTimeout;
   Timer _idleTimer;
 
   static Future<HttpServer> bind(address, int port, int backlog) {
     return ServerSocket.bind(address, port, backlog: backlog).then((socket) {
       return new _HttpServer._(socket, true);
     });
   }
 
@@ skipping 644 matching lines @@
   const _RedirectInfo(this.statusCode, this.method, this.location);
 }
 
 String _getHttpVersion() {
   var version = Platform.version;
   // Only include major and minor version numbers.
   int index = version.indexOf('.', version.indexOf('.') + 1);
   version = version.substring(0, index);
   return 'Dart/$version (dart:io)';
 }