Add a key purpose parameter to Certificate PathBuilder.

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 0cd2f70d2c54ffd70eb8a59e9028ff5f57df5f81..25afc28886d990b6003908f3735b7d441bfed2e2 100644
--- a/net/cert/internal/test_helpers.h
+++ b/net/cert/internal/test_helpers.h
@@ -13,6 +13,7 @@
 
 #include "net/cert/internal/parsed_certificate.h"
 #include "net/cert/internal/trust_store.h"
+#include "net/cert/internal/verify_certificate_chain.h"
 #include "net/der/input.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -91,6 +92,9 @@ struct VerifyCertChainTest {
   // The time to use when verifying the chain.
   der::GeneralizedTime time;
 
+  // The Key Purpose to use when verifying the chain.
+  KeyPurpose key_purpose = KeyPurpose::ANY_EKU;
+
   // The expected result from verification.
   bool expected_result = false;