Support GZip encoding on the http server.

tests/standalone/io/http_compression_test.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.
+//
+// VMOptions=
+// VMOptions=--short_socket_read
+// VMOptions=--short_socket_write
+// VMOptions=--short_socket_read --short_socket_write
+
+import 'dart:io';
+import 'dart:scalarlist';
+
+void testServerCompress() {
+  void test(List<int> data) {
+    HttpServer.bind().then((server) {
+      server.listen((request) {
+        request.response.writeBytes(data);
+        request.response.close();
+      });
+      var client = new HttpClient();
+      client.get("localhost", server.port, "/")
+          .then((request) {
+            request.headers.set(HttpHeaders.ACCEPT_ENCODING, "gzip");
+            return request.close();
+          })
+          .then((response) {
+            Expect.equals("gzip",
+                          response.headers.value(HttpHeaders.CONTENT_ENCODING));
+            response
+                .transform(new ZLibInflater())
+                .reduce([], (list, b) {
+                  list.addAll(b);
+                  return list;
+                }).then((list) {
+                  Expect.listEquals(data, list);
+                  server.close();
+                  client.close();
+                });
+          });
+    });
+  }
+  test("My raw server provided data".codeUnits);
+  var longBuffer = new Uint8List(1024 * 1024);
+  for (int i = 0; i < longBuffer.length; i++) {
+    longBuffer[i] = i & 0xFF;
+  }
+  test(longBuffer);
+}
+
+void main() {
+  testServerCompress();
+}