It's going to be removed from Chromium, see https://crbug.com/812523.

/cc @electron/code-owners 
chromium_src/chrome/browser/certificate_manager_model.cc
#include "chrome/browser/certificate_manager_model.h"
#include <utility>
#include "base/bind.h"
#include "base/logging.h"
#include "base/strings/utf_string_conversions.h"
#include "base/task/post_task.h"
#include "content/public/browser/browser_context.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/resource_context.h"
#include "crypto/nss_util.h"
#include "crypto/nss_util_internal.h"
#include "net/base/net_errors.h"
#include "net/cert/nss_cert_database.h"
#include "net/cert/x509_certificate.h"
using content::BrowserThread;
namespace {
net::NSSCertDatabase* g_nss_cert_database = nullptr;
net::NSSCertDatabase* GetNSSCertDatabaseForResourceContext(