Replace c/b/nss_context by a KeyedService.

chrome/browser/net/nss_context_linux.cc

-// Copyright (c) 2013 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/nss_context.h"
-
-#include "content/public/browser/browser_thread.h"
-#include "crypto/nss_util_internal.h"
-#include "net/cert/nss_cert_database.h"
-
-namespace {
-net::NSSCertDatabase* g_nss_cert_database = NULL;
-}  // namespace
-
-crypto::ScopedPK11Slot GetPublicNSSKeySlotForResourceContext(
-    content::ResourceContext* context) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
-  return crypto::ScopedPK11Slot(crypto::GetPersistentNSSKeySlot());
-}
-
-crypto::ScopedPK11Slot GetPrivateNSSKeySlotForResourceContext(
-    content::ResourceContext* context,
-    const base::Callback<void(crypto::ScopedPK11Slot)>& callback) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
-  return crypto::ScopedPK11Slot(crypto::GetPersistentNSSKeySlot());
-}
-
-net::NSSCertDatabase* GetNSSCertDatabaseForResourceContext(
-    content::ResourceContext* context,
-    const base::Callback<void(net::NSSCertDatabase*)>& callback) {
-  // This initialization is not thread safe. This CHECK ensures that this code
-  // is only run on a single thread.
-  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
-  if (!g_nss_cert_database) {
-    // Linux has only a single persistent slot compared to ChromeOS's separate
-    // public and private slot.
-    // Redirect any slot usage to this persistent slot on Linux.
-    g_nss_cert_database = new net::NSSCertDatabase(
-        crypto::ScopedPK11Slot(
-            crypto::GetPersistentNSSKeySlot()) /* public slot */,
-        crypto::ScopedPK11Slot(
-            crypto::GetPersistentNSSKeySlot()) /* private slot */);
-  }
-  return g_nss_cert_database;
-}