Provide mutable members of UrlRequestContext via pure-virtual interface

net/url_request/const_http_user_agent_settings.h

Index: net/url_request/const_http_user_agent_settings.h
diff --git a/net/url_request/const_http_user_agent_settings.h b/net/url_request/const_http_user_agent_settings.h
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index 0000000000000000000000000000000000000000..51f5775aae77db16b8d82d3d0800d6854e871d5b
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+++ b/net/url_request/const_http_user_agent_settings.h
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+// 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_CONST_HTTP_USER_AGENT_SETTINGS_H_
+#define NET_URL_REQUEST_CONST_HTTP_USER_AGENT_SETTINGS_H_
+
+#include "net/url_request/const_http_accept_language_and_charset.h"
+
+namespace net {
+
+// An implementation of |HttpUserAgentSettings| that always provides the
+// same constant values for the HTTP Accept-Language, Accept-Charset, and
+// User-Agent headers.
+class NET_EXPORT ConstHttpUserAgentSettings
+  : public ConstHttpAcceptLanguageAndCharset {
+ public:
+  ConstHttpUserAgentSettings(const std::string& accept_language,
+                             const std::string& accept_charset,
+                             const std::string& user_agent);
+  virtual ~ConstHttpUserAgentSettings() {}
+
+  // ConstHttpAcceptLanguageAndCharset implementation
+  virtual const std::string& GetUserAgent(const GURL& url) OVERRIDE;
+
+ private:
+  const std::string user_agent_;
+
+  DISALLOW_COPY_AND_ASSIGN(ConstHttpUserAgentSettings);
+};
+
+}  // namespace net
+
+#endif  // NET_URL_REQUEST_CONST_HTTP_USER_AGENT_SETTINGS_H_
+