Fix DeviceSyncCryptAuthV2EnrollerImplTest.Failure_MissingSessionId memory leaks

https://ci.chromium.org/p/chromium/builders/ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/33986
deterministic failures
DeviceSyncCryptAuthV2EnrollerImplTest.Failure_InvalidKeyCreationInstructions_NoServerDiffieHellman
DeviceSyncCryptAuthV2EnrollerImplTest.Failure_MissingClientDirective
DeviceSyncCryptAuthV2EnrollerImplTest.Failure_MissingSessionId
https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8910695961295961616/+/steps/chromeos_unittests/0/logs/Deterministic_failure:_DeviceSyncCryptAuthV2EnrollerImplTest.Failure_MissingSessionId__status_FAILURE_ON_EXIT_/0

Change-Id: If14d465bf335c44e7f288c13211299ac8be88426
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1660392
Auto-Submit: Takashi Sakamoto <tasak@google.com>
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669254}
1 file changed