Add a hook to inject trusted Cast roots for testing purposes.

extensions/common/cast/cast_cert_validator.cc

 // Copyright 2014 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 "extensions/common/cast/cast_cert_validator.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 274 matching lines @@
 }
 
 std::unique_ptr<CertVerificationContext> CertVerificationContextImplForTest(
     const base::StringPiece& spki) {
   // Use a bogus CommonName, since this is just exposed for testing signature
   // verification by unittests.
   return base::WrapUnique(
       new CertVerificationContextImpl(net::der::Input(spki), "CommonName"));
 }
 
+bool AddTrustAnchorForTest(const uint8_t* data, size_t length) {
+  return CastTrustStore::Get().AddTrustedCertificateWithoutCopying(data,
+                                                                   length);
+}
+
 }  // namespace cast_crypto
 }  // namespace api
 }  // namespace extensions