Replace c/b/nss_context by a KeyedService.

components/cert_database/core/cert_database_service_io_part.cc

+// 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.
+
+#include "components/cert_database/public/cert_database_service_io_part.h"
+
+#include "base/callback.h"
+#include "net/cert/nss_cert_database.h"
+
+namespace cert_database {
+
+CertDatabaseServiceIOPart::CertDatabaseServiceIOPart()
+    : weak_ptr_factory_(this) {
+}
+
+CertDatabaseServiceIOPart::~CertDatabaseServiceIOPart() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void CertDatabaseServiceIOPart::Init() {
+  // Init determines the thread to attach to.
+  thread_checker_.DetachFromThread();
+  thread_checker_.CalledOnValidThread();
+}
+
+net::NSSCertDatabase* CertDatabaseServiceIOPart::GetNSSCertDatabase(
+    const base::Callback<void(net::NSSCertDatabase*)>& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (nss_cert_database_)
+    return nss_cert_database_.get();
+
+  get_cert_db_callbacks_.push_back(callback);
+  return NULL;
+}
+
+base::WeakPtr<CertDatabaseServiceIOPart>
+CertDatabaseServiceIOPart::GetWeakPtr() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return weak_ptr_factory_.GetWeakPtr();
+}
+
+void CertDatabaseServiceIOPart::DidCreateNSSCertDatabase(
+    scoped_ptr<net::NSSCertDatabase> db) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  nss_cert_database_ = db.Pass();
+  for (GetCertDBCallbacks::iterator i = get_cert_db_callbacks_.begin();
+       i != get_cert_db_callbacks_.end();
+       ++i) {
+    i->Run(nss_cert_database_.get());
+  }
+  get_cert_db_callbacks_.clear();
+}
+
+}  // namespace cert_database