Revert of Cast device revocation checking.

components/cast_certificate/cast_cert_validator_test_helpers.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 COMPONENTS_CAST_CERTIFICATE_CAST_CERT_VALIDATOR_TEST_HELPERS_H_
 #define COMPONENTS_CAST_CERTIFICATE_CAST_CERT_VALIDATOR_TEST_HELPERS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 17 matching lines @@
 
   // RSASSA PKCS#1 v1.5 with SHA256.
   std::string signature_sha256;
 };
 
 // Reads a PEM file that contains "MESSAGE", "SIGNATURE SHA1" and
 // "SIGNATURE SHA256" blocks.
 // |file_name| should be relative to //components/test/data/cast_certificate
 SignatureTestData ReadSignatureTestData(const base::StringPiece& file_name);
 
-// Reads a file from the test data directory
-// (//src/components/test/data/cast_certificate)
-std::string ReadTestFileToString(const base::StringPiece& file_name);
-
 }  // namespace testing
 
 }  // namespace cast_certificate
 
 #endif  // COMPONENTS_CAST_CERTIFICATE_CAST_CERT_VALIDATOR_TEST_HELPERS_H_