Add CertIssuerSource interface and CertIssuerSourceStatic implementation.

net/cert/internal/cert_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_source_static.h"
+
+#include "net/cert/internal/parsed_certificate.h"
+
+namespace net {
+
+CertSourceStatic::CertSourceStatic() {}
+CertSourceStatic::~CertSourceStatic() {}
+
+void CertSourceStatic::AddCert(scoped_refptr<ParsedCertificate> cert) {
+  intermediates_.insert(std::make_pair(
+      cert->normalized_subject().AsStringPiece(), std::move(cert)));
+}
+
+void CertSourceStatic::SyncGetIssuersOf(
+    const ParsedCertificate* cert,
+    std::vector<scoped_refptr<ParsedCertificate>>* 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 CertSourceStatic::AsyncGetIssuersOf(const ParsedCertificate* cert,
+                                         const IssuerCallback& issuers_callback,
+                                         std::unique_ptr<Request>* out_req) {
+  // CertSourceStatic never returns asynchronous results.
+  out_req->reset();
+}
+
+}  // namespace net