Move CertVerifyProcMac unit-tests to their own file.

Review-Url: https://codereview.chromium.org/2670643008
Cr-Commit-Position: refs/heads/master@{#448111}
diff --git a/net/test/cert_test_util.h b/net/test/cert_test_util.h
index f948bd8..f5b104b1 100644
--- a/net/test/cert_test_util.h
+++ b/net/test/cert_test_util.h
@@ -10,6 +10,7 @@
 #include "base/memory/ref_counted.h"
 #include "net/cert/x509_cert_types.h"
 #include "net/cert/x509_certificate.h"
+#include "testing/gtest/include/gtest/gtest.h"
 
 #if defined(USE_NSS_CERTS)
 // From <pk11pub.h>
@@ -48,6 +49,13 @@
                                               const std::string& cert_file,
                                               int format);
 
+// Imports all the certificates given a list of filenames, and assigns the
+// result to |*certs|. The filenames are relative to the test certificates
+// directory.
+::testing::AssertionResult LoadCertificateFiles(
+    const std::vector<std::string>& cert_filenames,
+    CertificateList* certs);
+
 // Imports all of the certificates in |cert_file|, a file in |certs_dir|, into
 // a new X509Certificate. The first certificate in the chain will be used for
 // the returned cert, with any additional certificates configured as