Implement HttpUserAgentSettings delegate for Android WebView

android_webview/browser/net/aw_http_user_agent_settings.h

+// Copyright (c) 2015 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 ANDROID_WEBVIEW_BROWSER_NET_AW_HTTP_USER_AGENT_SETTINGS_H_
+#define ANDROID_WEBVIEW_BROWSER_NET_AW_HTTP_USER_AGENT_SETTINGS_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "net/url_request/http_user_agent_settings.h"
+
+namespace android_webview {
+
+// An implementation of |HttpUserAgentSettings| that provides HTTP header
+// Accept-Language value that tracks aw accept language.
+class AwHttpUserAgentSettings : public net::HttpUserAgentSettings {
+ public:
+  // Must be called on the UI thread.
+  AwHttpUserAgentSettings();
+  // Must be called on the IO thread.
+  ~AwHttpUserAgentSettings() override;
+
+  // net::HttpUserAgentSettings implementation
+  std::string GetAcceptLanguage() const override;
+  std::string GetUserAgent() const override;
+
+ private:
+  // Avoid re-processing by caching the last value from the locale and the
+  // last result of processing via net::HttpUtil::GenerateAccept*Header().
+  mutable std::string last_aw_accept_language_;
+  mutable std::string last_http_accept_language_;
+
+  DISALLOW_COPY_AND_ASSIGN(AwHttpUserAgentSettings);
+};
+
+}  // namespace android_webview
+
+#endif  // ANDROID_WEBVIEW_BROWSER_NET_AW_HTTP_USER_AGENT_SETTINGS_H_
+