Provide mutable members of UrlRequestContext via pure-virtual interface

net/url_request/http_user_agent_settings.h

Index: net/url_request/http_user_agent_settings.h
diff --git a/net/url_request/http_user_agent_settings.h b/net/url_request/http_user_agent_settings.h
new file mode 100644
index 0000000000000000000000000000000000000000..1011f8294ca617c763cf02e72fe94c8e4c71977b
--- /dev/null
+++ b/net/url_request/http_user_agent_settings.h
@@ -0,0 +1,37 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_URL_REQUEST_HTTP_USER_AGENT_SETTINGS_H_
+#define NET_URL_REQUEST_HTTP_USER_AGENT_SETTINGS_H_
+
+#include <string>
+
+#include "net/base/net_export.h"
+
+class GURL;
+
+namespace net {
+
+// The interface used by HTTP jobs to retrieve HTTP Accept-Language,
+// Accept-Charset and User-Agent header values.
+class NET_EXPORT HttpUserAgentSettings {
+ public:
+  // Gets the value of 'Accept-Language' header field.
+  virtual const std::string& GetAcceptLanguage() = 0;
+
+  // Gets the value of 'Accept-Charset' header field.
+  virtual const std::string& GetAcceptCharset() = 0;
+
+  // Gets the UA string to use for the given URL.  Pass an empty URL to get
+  // the default UA string.
+  virtual const std::string& GetUserAgent(const GURL& url) = 0;
+
+  HttpUserAgentSettings() {}
+  virtual ~HttpUserAgentSettings() {}
+};
+
+}  // namespace net
+
+#endif  // NET_URL_REQUEST_HTTP_USER_AGENT_SETTINGS_H_
+