Multiple Renewal Keys and Logging

In this code update we add a test to ensure that the White-box API
implementation handle seeing multiple renewal keys correctly. Since
there should be no more than one renewal key in a license response, upon
seeing a second renewal key, the implementation should return a
WB_RESULT_INVALID_PARAMETER code.

Due to changes in how Chrome manages CHECKS and DCHECKS, this code has
been updated to use the new headers.

impl/reference/aead_whitebox_impl.cc

@@ -5,6 +5,7 @@
 #include <memory>
 #include <vector>
 
+#include "base/check_op.h"
 #include "base/logging.h"
 #include "crypto_utils/crypto_util.h"
 #include "impl/reference/memory_util.h"