Replace c/b/nss_context by a KeyedService.

chrome/browser/net/cert_database_service_factory_linux.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 "chrome/browser/net/cert_database_service_factory.h"
+
+#include "base/memory/scoped_ptr.h"
+#include "components/cert_database/cert_database_service.h"
+#include "components/cert_database/cert_database_service_io_part_linux.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace cert_database {
+
+KeyedService* CertDatabaseServiceFactory::BuildServiceInstanceFor(
+    content::BrowserContext* context) const {
+  scoped_ptr<CertDatabaseServiceIOPart> io_part(
+      new CertDatabaseServiceIOPartLinux());
+
+  scoped_ptr<CertDatabaseService> service(new CertDatabaseService(
+      content::BrowserThread::GetMessageLoopProxyForThread(
+          content::BrowserThread::IO)));
+
+  // After this point, the IOPart must only be accessed from the IO thread!
+  service->SetIOPart(io_part.Pass());
+
+  return service.release();
+}
+
+}  // namespace cert_database