Add CertIssuerSource interface and CertIssuerSourceStatic implementation.

net/cert/internal/cert_source_static.h

+// 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.
+
+#ifndef NET_CERT_INTERNAL_CERT_SOURCE_STATIC_H_
+#define NET_CERT_INTERNAL_CERT_SOURCE_STATIC_H_
+
+#include <unordered_map>
+
+#include "base/strings/string_piece.h"
+#include "net/cert/internal/cert_source.h"
+
+namespace net {
+
+// Synchronously returns issuers from a pre-supplied set.
+class NET_EXPORT CertSourceStatic : public CertSource {
+ public:
+  CertSourceStatic();
+  ~CertSourceStatic() override;
+
+  // Adds |cert| to the set of certificates that this CertSource will provide.
+  void AddCert(scoped_refptr<ParsedCertificate> cert);
+
+  // CertSource implementation:
+  void SyncGetIssuersOf(
+      const ParsedCertificate* cert,
+      std::vector<scoped_refptr<ParsedCertificate>>* issuers) override;
+  void AsyncGetIssuersOf(const ParsedCertificate* cert,
+                         const IssuerCallback& issuers_callback,
+                         std::unique_ptr<Request>* out_req) override;
+
+ private:
+  // The certificates that the CertSourceStatic can return, keyed on the
+  // normalized subject value.
+  std::unordered_multimap<base::StringPiece,
+                          scoped_refptr<ParsedCertificate>,
+                          base::StringPieceHash>
+      intermediates_;
+
+  DISALLOW_COPY_AND_ASSIGN(CertSourceStatic);
+};
+
+}  // namespace net
+
+#endif  // NET_CERT_INTERNAL_CERT_SOURCE_STATIC_H_