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

net/cert/internal/test_helpers.h

Index: net/cert/internal/test_helpers.h
diff --git a/net/cert/internal/test_helpers.h b/net/cert/internal/test_helpers.h
index 99405ba8e5f3bdcea3ad8c802e5ec86b807f0c3b..9e5ddfbf09ebf0ae45d1f89321d8f62d89a2ed2b 100644
--- a/net/cert/internal/test_helpers.h
+++ b/net/cert/internal/test_helpers.h
@@ -5,6 +5,7 @@
 #ifndef NET_CERT_INTERNAL_TEST_HELPERS_H_
 #define NET_CERT_INTERNAL_TEST_HELPERS_H_
 
+#include <ostream>
 #include <string>
 #include <vector>
 
@@ -13,6 +14,15 @@
 
 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:
 //