In addition to that, TPM 2.0 doesn't mark any errors as transient, so that also should be fixed.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/5af5a923e26c4099fde71aae71fff8a1af49a9f3

commit 5af5a923e26c4099fde71aae71fff8a1af49a9f3
Author: Andrey Pronin <apronin@chromium.org>
Date: Tue Mar 14 02:58:50 2017

cryptohome: fix transient error logic for tpm2

Use the same IsTransient() logic to determine if the retry action
corresponds to a transient tpm error for TPM 2.0 case, as was used
for TPM 1.2.

IsTransient() is used to determine if a transient error occurred
when loading the cryptohome key, so that loading just needs to
be retried at a later time, instead of re-creating the key.

Map tpm device write/read errors to CommFailure retry action,
which is considered to be transient.

BUG= chromium:699240 
TEST=Unit tests (new added)

Change-Id: I03ae89dec9a69a371edc2e0df700ec50f50c23fd
Reviewed-on: https://chromium-review.googlesource.com/452729
Commit-Ready: Andrey Pronin <apronin@chromium.org>
Tested-by: Andrey Pronin <apronin@chromium.org>
Reviewed-by: Darren Krahn <dkrahn@chromium.org>

[modify] https://crrev.com/5af5a923e26c4099fde71aae71fff8a1af49a9f3/cryptohome/tpm2_test.cc
[modify] https://crrev.com/5af5a923e26c4099fde71aae71fff8a1af49a9f3/cryptohome/tpm2_impl.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/11d7e9e21859ad4802e24545004d90d4ac8c6ca6

commit 11d7e9e21859ad4802e24545004d90d4ac8c6ca6
Author: Andrey Pronin <apronin@chromium.org>
Date: Tue Mar 14 02:58:50 2017

cryptohome: don't re-create the key on transient tpm errors

If a transient error (e.g. tpm communication failure) occurs
when loading the cryptohome key, cryptohomed now doesn't
re-create the key. It just leaves the key unloaded, and it is
attempted to load again next time Crypto::EnsureTpm is called.

Without that, a single communication issue could trigger making
homes for existing users unmountable, and losing local user data.

Restores the behavior unintentionally modified by CL:261466.

BUG= chromium:699240 
TEST=1) Unit tests (new added).
     2) Imitate transient comm error, verify that logging in
        succeeds once the error is gone, and local files in
        Downloads are left intact.

Change-Id: I1657c5e546ada10ea81ca5de131695b8cb0df99a
Reviewed-on: https://chromium-review.googlesource.com/452761
Commit-Ready: Andrey Pronin <apronin@chromium.org>
Tested-by: Andrey Pronin <apronin@chromium.org>
Reviewed-by: Darren Krahn <dkrahn@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>

[modify] https://crrev.com/11d7e9e21859ad4802e24545004d90d4ac8c6ca6/cryptohome/tpm_init.h
[modify] https://crrev.com/11d7e9e21859ad4802e24545004d90d4ac8c6ca6/cryptohome/tpm_init_unittest.cc
[modify] https://crrev.com/11d7e9e21859ad4802e24545004d90d4ac8c6ca6/cryptohome/tpm_init.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/67d8b325813901fa91424a3d3181bb9156d939d7

commit 67d8b325813901fa91424a3d3181bb9156d939d7
Author: Andrey Pronin <apronin@chromium.org>
Date: Mon Mar 20 18:01:05 2017

cryptohome: don't re-create the key on transient tpm errors

If a transient error (e.g. tpm communication failure) occurs
when loading the cryptohome key, cryptohomed now doesn't
re-create the key. It just leaves the key unloaded, and it is
attempted to load again next time Crypto::EnsureTpm is called.

Without that, a single communication issue could trigger making
homes for existing users unmountable, and losing local user data.

Restores the behavior unintentionally modified by CL:261466.

BUG= chromium:699240 
TEST=1) Unit tests (new added).
     2) Imitate transient comm error, verify that logging in
        succeeds once the error is gone, and local files in
        Downloads are left intact.

Change-Id: I1657c5e546ada10ea81ca5de131695b8cb0df99a
Reviewed-on: https://chromium-review.googlesource.com/452761
Commit-Ready: Andrey Pronin <apronin@chromium.org>
Tested-by: Andrey Pronin <apronin@chromium.org>
Reviewed-by: Darren Krahn <dkrahn@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
(cherry picked from commit 11d7e9e21859ad4802e24545004d90d4ac8c6ca6)
Reviewed-on: https://chromium-review.googlesource.com/456635
Reviewed-by: Andrey Pronin <apronin@chromium.org>
Commit-Queue: Andrey Pronin <apronin@chromium.org>

[modify] https://crrev.com/67d8b325813901fa91424a3d3181bb9156d939d7/cryptohome/tpm_init.h
[modify] https://crrev.com/67d8b325813901fa91424a3d3181bb9156d939d7/cryptohome/tpm_init_unittest.cc
[modify] https://crrev.com/67d8b325813901fa91424a3d3181bb9156d939d7/cryptohome/tpm_init.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/67d8b325813901fa91424a3d3181bb9156d939d7

commit 67d8b325813901fa91424a3d3181bb9156d939d7
Author: Andrey Pronin <apronin@chromium.org>
Date: Mon Mar 20 18:01:05 2017

cryptohome: don't re-create the key on transient tpm errors

If a transient error (e.g. tpm communication failure) occurs
when loading the cryptohome key, cryptohomed now doesn't
re-create the key. It just leaves the key unloaded, and it is
attempted to load again next time Crypto::EnsureTpm is called.

Without that, a single communication issue could trigger making
homes for existing users unmountable, and losing local user data.

Restores the behavior unintentionally modified by CL:261466.

BUG= chromium:699240 
TEST=1) Unit tests (new added).
     2) Imitate transient comm error, verify that logging in
        succeeds once the error is gone, and local files in
        Downloads are left intact.

Change-Id: I1657c5e546ada10ea81ca5de131695b8cb0df99a
Reviewed-on: https://chromium-review.googlesource.com/452761
Commit-Ready: Andrey Pronin <apronin@chromium.org>
Tested-by: Andrey Pronin <apronin@chromium.org>
Reviewed-by: Darren Krahn <dkrahn@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
(cherry picked from commit 11d7e9e21859ad4802e24545004d90d4ac8c6ca6)
Reviewed-on: https://chromium-review.googlesource.com/456635
Reviewed-by: Andrey Pronin <apronin@chromium.org>
Commit-Queue: Andrey Pronin <apronin@chromium.org>

[modify] https://crrev.com/67d8b325813901fa91424a3d3181bb9156d939d7/cryptohome/tpm_init.h
[modify] https://crrev.com/67d8b325813901fa91424a3d3181bb9156d939d7/cryptohome/tpm_init_unittest.cc
[modify] https://crrev.com/67d8b325813901fa91424a3d3181bb9156d939d7/cryptohome/tpm_init.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/6f2f9974fcf4d08964519f4280cc1dd671c30757

commit 6f2f9974fcf4d08964519f4280cc1dd671c30757
Author: Andrey Pronin <apronin@chromium.org>
Date: Mon Mar 20 18:01:07 2017

cryptohome: fix transient error logic for tpm2

Use the same IsTransient() logic to determine if the retry action
corresponds to a transient tpm error for TPM 2.0 case, as was used
for TPM 1.2.

IsTransient() is used to determine if a transient error occurred
when loading the cryptohome key, so that loading just needs to
be retried at a later time, instead of re-creating the key.

Map tpm device write/read errors to CommFailure retry action,
which is considered to be transient.

BUG= chromium:699240 
TEST=Unit tests (new added)

Change-Id: I03ae89dec9a69a371edc2e0df700ec50f50c23fd
Reviewed-on: https://chromium-review.googlesource.com/452729
Commit-Ready: Andrey Pronin <apronin@chromium.org>
Tested-by: Andrey Pronin <apronin@chromium.org>
Reviewed-by: Darren Krahn <dkrahn@chromium.org>
(cherry picked from commit 5af5a923e26c4099fde71aae71fff8a1af49a9f3)
Reviewed-on: https://chromium-review.googlesource.com/457416
Reviewed-by: Andrey Pronin <apronin@chromium.org>
Commit-Queue: Andrey Pronin <apronin@chromium.org>

[modify] https://crrev.com/6f2f9974fcf4d08964519f4280cc1dd671c30757/cryptohome/tpm2_test.cc
[modify] https://crrev.com/6f2f9974fcf4d08964519f4280cc1dd671c30757/cryptohome/tpm2_impl.cc