Remove dependence on a message loop for net::PathBuilder.

net/cert/internal/cert_issuer_source_static.cc

 // Copyright 2016 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 "net/cert/internal/cert_issuer_source_static.h"
 
 namespace net {
 
 CertIssuerSourceStatic::CertIssuerSourceStatic() = default;
 CertIssuerSourceStatic::~CertIssuerSourceStatic() = default;
 
 void CertIssuerSourceStatic::AddCert(scoped_refptr<ParsedCertificate> cert) {
   intermediates_.insert(std::make_pair(
       cert->normalized_subject().AsStringPiece(), std::move(cert)));
 }
 
 void CertIssuerSourceStatic::SyncGetIssuersOf(const ParsedCertificate* cert,
                                               ParsedCertificateList* issuers) {
   auto range =
       intermediates_.equal_range(cert->normalized_issuer().AsStringPiece());
   for (auto it = range.first; it != range.second; ++it)
     issuers->push_back(it->second);
 }
 
 void CertIssuerSourceStatic::AsyncGetIssuersOf(
     const ParsedCertificate* cert,
-    const IssuerCallback& issuers_callback,
     std::unique_ptr<Request>* out_req) {
   // CertIssuerSourceStatic never returns asynchronous results.
   out_req->reset();
 }
 
 }  // namespace net