Prepare to abstract PersistedData by making it part of the configurator.

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>
 
@@ skipping 28 matching lines @@
   std::string GetDownloadPreference() const override;
   net::URLRequestContextGetter* RequestContext() const override;
   scoped_refptr<update_client::OutOfProcessPatcher> CreateOutOfProcessPatcher()
       const override;
   bool EnabledDeltas() const override;
   bool EnabledComponentUpdates() const override;
   bool EnabledBackgroundDownloader() const override;
   bool EnabledCupSigning() const override;
   PrefService* GetPrefService() const override;
   bool IsPerUserInstall() const override;
+  update_client::PersistedData* CreateMetadata() const override;

[waffles, 2017/05/12 17:33:34]

Can we return a unique_ptr instead?

[Minh X. Nguyen, 2017/05/14 23:57:22]

Done.

 
  protected:
   friend class base::RefCountedThreadSafe<ChromeUpdateClientConfig>;
   ~ChromeUpdateClientConfig() override;
 
  private:
   component_updater::ConfiguratorImpl impl_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeUpdateClientConfig);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_UPDATER_CHROME_UPDATE_CLIENT_CONFIG_H_