Replace c/b/nss_context by a KeyedService.

components/cert_database/public/chromeos/cert_database_service_io_part_chromeos.h

+// Copyright 2014 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 COMPONENTS_CERT_DATABASE_PUBLIC_CHROMEOS_CERT_DATABASE_SERVICE_IO_PART_CHROMEOS_H_
+#define COMPONENTS_CERT_DATABASE_PUBLIC_CHROMEOS_CERT_DATABASE_SERVICE_IO_PART_CHROMEOS_H_
+
+#include <string>
+
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner.h"
+#include "components/cert_database/public/cert_database_service_io_part.h"
+
+namespace chromeos {
+class CryptohomeClient;
+}
+
+namespace cert_database {
+
+class CertDatabaseServiceIOPartChromeOS : public CertDatabaseServiceIOPart {
+ public:
+  typedef base::Callback<void(bool system_tpm_token_enabled)>
+      SystemTPMTokenReadyCallback;
+
+  CertDatabaseServiceIOPartChromeOS(
+      const std::string& user_email,
+      const std::string& username_hash,
+      bool use_system_key_slot,
+      const base::FilePath& path,
+      const scoped_refptr<base::SequencedTaskRunner>& dbus_task_runner,
+      chromeos::CryptohomeClient* cryptohome_client);
+
+  ~CertDatabaseServiceIOPartChromeOS() override;
+
+  void Init() override;
+
+  // Returns a callback that must be called at most once to signal that the
+  // system TPM token is ready (disabled or enabled).
+  // This function may only be called before Init(). However, the callback must
+  // be called after Init() on the IO thread.

[mattm, 2014/10/30 03:37:48]

confusing wording, maybe
"the callback must be called after Init(), and must be called on the IO thread."

[pneubeck (no reviews), 2014/11/05 14:53:37]

Done.

+  SystemTPMTokenReadyCallback GetSystemTPMTokenReadyCallback();
+
+ protected:
+  void DidCreateNSSCertDatabase(scoped_ptr<net::NSSCertDatabase> db);
+
+ private:
+  class Internal;
+  scoped_ptr<Internal> internal_;
+
+  DISALLOW_COPY_AND_ASSIGN(CertDatabaseServiceIOPartChromeOS);
+};
+
+}  // namespace cert_database
+
+#endif  // COMPONENTS_CERT_DATABASE_PUBLIC_CHROMEOS_CERT_DATABASE_SERVICE_IO_PART_CHROMEOS_H_