Roll src/third_party/cros_system_api/ e831a312c..938e6c463 (3 commits)

https://chromium.googlesource.com/chromiumos/platform2/system_api.git/+log/e831a312c4ab..938e6c463847

$ git log e831a312c..938e6c463 --date=short --no-merges --format='%ad %ae %s'
2020-01-15 ljusten authpolicy, kerberos: Update owners, clean up
2020-01-17 emaxx system_api: Add constant for "TPM update required"
2020-01-07 victorhsieh system_api: generate boot lockbox's Go proto binding

Created with:
  roll-dep src/third_party/cros_system_api

Bug: 1011327
Change-Id: I6dfd3136e2c4c37e599c3b89f5cd9e045d335a49
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2007418Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#733577}

DEPS

@@ -894,7 +894,7 @@ deps = {
 
   # For Linux and Chromium OS.
   'src/third_party/cros_system_api': {
-      'url': Var('chromium_git') + '/chromiumos/platform2/system_api.git' + '@' + 'e831a312c4ab87704a1139852c276797c47f7e4a',
+      'url': Var('chromium_git') + '/chromiumos/platform2/system_api.git' + '@' + '938e6c4638472c79ed28356d95b65dfc9ec82df5',
       'condition': 'checkout_linux',
   },