Certificate Transparency: Wire the TreeStateTracker up.

chrome/browser/component_updater/sth_set_component_installer.h

 // Copyright 2016 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_COMPONENT_UPDATER_STH_SET_COMPONENT_INSTALLER_H_
 #define CHROME_BROWSER_COMPONENT_UPDATER_STH_SET_COMPONENT_INSTALLER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 22 matching lines @@
 // Transparency logs recognized in Chrome.
 // The STHs are in JSON format.
 // To identify the log each STH belongs to, the name of the file is
 // hex-encoded Log ID of the log that produced this STH.
 //
 // Notifications of each of the new STHs are sent to the net::ct::STHObserver,
 // so that it can take appropriate steps, including possible persistence.
 class STHSetComponentInstallerTraits : public ComponentInstallerTraits {
  public:
   // The |sth_distributor| will be notified each time a new STH is observed.
-  explicit STHSetComponentInstallerTraits(
-      std::unique_ptr<net::ct::STHObserver> sth_observer);
+  explicit STHSetComponentInstallerTraits(net::ct::STHObserver* sth_observer);
   ~STHSetComponentInstallerTraits() override;
 
  private:
   friend class STHSetComponentInstallerTest;
 
   // ComponentInstallerTraits implementation.
   bool CanAutoUpdate() const override;
   bool RequiresNetworkEncryption() const override;
   bool OnCustomInstall(const base::DictionaryValue& manifest,
                        const base::FilePath& install_dir) override;
@@ skipping 11 matching lines @@
   void LoadSTHsFromDisk(const base::FilePath& sths_file_path,
                         const base::Version& version);
 
   // Handle successful parsing of JSON by distributing the new STH.
   void OnJsonParseSuccess(const std::string& log_id,
                           std::unique_ptr<base::Value> parsed_json);
 
   // STH parsing failed - do nothing.
   void OnJsonParseError(const std::string& log_id, const std::string& error);
 
-  std::unique_ptr<net::ct::STHObserver> sth_observer_;
+  net::ct::STHObserver* sth_observer_;

[Sorin Jianu, 2016/05/25 16:17:48]

Would it be possible to use a smart pointer? Same question for the constructor
parameter.

[Eran Messeri, 2016/05/25 16:26:18]

The two smart pointers I could use here are:
unique_ptr: Means passing ownership into STHSetComponentInstallerTraits, which,
as we discussed earlier, would complicate wiring and lifecycle management of
everything that's registered on it.
scoped_refptr: Means reference-counting the STHObserver. But because a global
object is now used to access it I don't see much value.

 
   DISALLOW_COPY_AND_ASSIGN(STHSetComponentInstallerTraits);
 };
 
 void RegisterSTHSetComponent(ComponentUpdateService* cus,
                              const base::FilePath& user_data_dir);
 
 }  // namespace component_updater
 
 #endif  // CHROME_BROWSER_COMPONENT_UPDATER_STH_SET_COMPONENT_INSTALLER_H_