Add extensions code to use common updater in components/update_client/

chrome/browser/extensions/updater/chrome_update_client_config.h

+// Copyright 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 CHROME_BROWSER_EXTENSIONS_UPDATER_CHROME_UPDATE_CLIENT_CONFIG_H_
+#define CHROME_BROWSER_EXTENSIONS_UPDATER_CHROME_UPDATE_CLIENT_CONFIG_H_
+
+#include <string>
+#include <vector>
+
+#include "extensions/browser/updater/update_client_config.h"
+
+namespace extensions {
+
+class ChromeUpdateClientConfig : public UpdateClientConfig {
+ public:
+  explicit ChromeUpdateClientConfig(content::BrowserContext* context);
+
+  std::vector<GURL> UpdateUrl() const override;
+  std::vector<GURL> PingUrl() const override;
+
+  base::Version GetBrowserVersion() const override;
+  std::string GetChannel() const override;
+  std::string GetLang() const override;
+
+ private:
+  friend class base::RefCountedThreadSafe<ChromeUpdateClientConfig>;
+  ~ChromeUpdateClientConfig() override;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_UPDATER_CHROME_UPDATE_CLIENT_CONFIG_H_