Add a function for parsing RFC 5280's "Certificate".

net/cert/internal/test_helpers.h

 // Copyright 2015 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_TEST_HELPERS_H_
 #define NET_CERT_INTERNAL_TEST_HELPERS_H_
 
+#include <ostream>
 #include <string>
 #include <vector>
 
 #include "net/der/input.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 
+namespace der {
+
+// These functions are used by GTest to support EXPECT_EQ() for
+// der::Input.
+void PrintTo(const Input& data, ::std::ostream* os);
+bool operator==(const Input& a, const Input& b);
+
+}  // namespace der
+
 // Creates a der::Input from an std::string. The lifetimes are a bit subtle
 // when using this function:
 //
 // The returned der::Input() is only valid so long as the input string is alive
 // and is not mutated.
 //
 // Note that the input parameter has been made a pointer to prevent callers
 // from accidentally passing an r-value.
 der::Input InputFromString(const std::string* s);
 
@@ skipping 29 matching lines @@
 template <size_t N>
 ::testing::AssertionResult ReadTestDataFromPemFile(
     const std::string& file_path_ascii,
     const PemBlockMapping(&mappings)[N]) {
   return ReadTestDataFromPemFile(file_path_ascii, mappings, N);
 }
 
 }  // namespace net
 
 #endif  // NET_CERT_INTERNAL_TEST_HELPERS_H_