Make some HTTP utility functions public

sdk/lib/io/http_headers.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 _HttpHeaders implements HttpHeaders {
   _HttpHeaders(String this.protocolVersion)
       : _headers = new Map<String, List<String>>();
 
@@ skipping 122 matching lines @@
   void set port(int port) {
     _checkMutable();
     _port = port;
     _updateHostHeader();
   }
 
   DateTime get ifModifiedSince {
     List<String> values = _headers[HttpHeaders.IF_MODIFIED_SINCE];
     if (values != null) {
       try {
-        return _HttpUtils.parseDate(values[0]);
+        return HttpDate.parse(values[0]);
       } on Exception catch (e) {
         return null;
       }
     }
     return null;
   }
 
   void set ifModifiedSince(DateTime ifModifiedSince) {
     _checkMutable();
     // Format "ifModifiedSince" header with date in Greenwich Mean Time (GMT).
-    String formatted = _HttpUtils.formatDate(ifModifiedSince.toUtc());
+    String formatted = HttpDate.format(ifModifiedSince.toUtc());
     _set(HttpHeaders.IF_MODIFIED_SINCE, formatted);
   }
 
   DateTime get date {
     List<String> values = _headers[HttpHeaders.DATE];
     if (values != null) {
       try {
-        return _HttpUtils.parseDate(values[0]);
+        return HttpDate.parse(values[0]);
       } on Exception catch (e) {
         return null;
       }
     }
     return null;
   }
 
   void set date(DateTime date) {
     _checkMutable();
     // Format "DateTime" header with date in Greenwich Mean Time (GMT).
-    String formatted = _HttpUtils.formatDate(date.toUtc());
+    String formatted = HttpDate.format(date.toUtc());
     _set("date", formatted);
   }
 
   DateTime get expires {
     List<String> values = _headers[HttpHeaders.EXPIRES];
     if (values != null) {
       try {
-        return _HttpUtils.parseDate(values[0]);
+        return HttpDate.parse(values[0]);
       } on Exception catch (e) {
         return null;
       }
     }
     return null;
   }
 
   void set expires(DateTime expires) {
     _checkMutable();
     // Format "Expires" header with date in Greenwich Mean Time (GMT).
-    String formatted = _HttpUtils.formatDate(expires.toUtc());
+    String formatted = HttpDate.format(expires.toUtc());
     _set(HttpHeaders.EXPIRES, formatted);
   }
 
   ContentType get contentType {
     var values = _headers["content-type"];
     if (values != null) {
       return ContentType.parse(values[0]);
     } else {
       return null;
     }
@@ skipping 78 matching lines @@
     }
   }
 
   void _addValue(String name, Object value) {
     List<String> values = _headers[name];
     if (values == null) {
       values = new List<String>();
       _headers[name] = values;
     }
     if (value is DateTime) {
-      values.add(_HttpUtils.formatDate(value));
+      values.add(HttpDate.format(value));
     } else {
       values.add(value.toString());
     }
   }
 
   void _set(String name, String value) {
     name = name.toLowerCase();
     List<String> values = new List<String>();
     _headers[name] = values;
     values.add(value);
@@ skipping 441 matching lines @@
     parseAttributes();
   }
 
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.write(name);
     sb.write("=");
     sb.write(value);
     if (expires != null) {
       sb.write("; Expires=");
-      sb.write(_HttpUtils.formatDate(expires));
+      sb.write(HttpDate.format(expires));
     }
     if (maxAge != null) {
       sb.write("; Max-Age=");
       sb.write(maxAge);
     }
     if (domain != null) {
       sb.write("; Domain=");
       sb.write(domain);
     }
     if (path != null) {
       sb.write("; Path=");
       sb.write(path);
     }
     if (secure) sb.write("; Secure");
     if (httpOnly) sb.write("; HttpOnly");
     return sb.toString();
   }
 
   String name;
   String value;
   DateTime expires;
   int maxAge;
   String domain;
   String path;
   bool httpOnly = false;
   bool secure = false;
 }