[Android Refactor] Merge WebappDataStorage#LAST_USED_UNSET and LAST_USED_INVALID

[Android Refactor] Merge WebappDataStorage#LAST_USED_UNSET and LAST_USED_INVALID

Having both LAST_USED_UNSET and LAST_USED_INVALID is unnecessary as
- the "last_used" SharedPreference should never be set to LAST_USED_INVALID
- there isn't any logic which checks whether "last_used" is LAST_USED_INVALID

Additionally, this CL renames LAST_USED_INVALID to TIMESTAMP_INVALID as
the getters for several time-based SharedPreferences other than "last_used"
return LAST_USED_INVALID if the preference is unset.

BUG=None

Review-Url: https://codereview.chromium.org/2927723003
Cr-Commit-Position: refs/heads/master@{#478067}
Committed: https://chromium.googlesource.com/chromium/src/+/618fd4f3564ecc43f4f7bff660c22a9dd5fc2309

[pkotwicz, 2017-06-08 04:55:58]

pkotwicz@chromium.org changed reviewers:
+ dominickn@chromium.org

[pkotwicz, 2017-06-08 04:55:58]

Dominick, can you please take a look?

[dominickn, 2017-06-08 05:22:44]

lgtm assuming it passes the CQ

[pkotwicz, 2017-06-08 18:11:39]

The CQ bit was checked by pkotwicz@chromium.org

[commit-bot: I haz the power, 2017-06-08 18:12:16]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-08 20:11:02]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496945499591950, "parent_rev":
"bafbc3fe297223ffbef775053a1407910ce730e6", "commit_rev":
"15205e10582c5d6f26d465f8f532fd111710b007"}

[commit-bot: I haz the power, 2017-06-08 20:11:15]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496945499591950, "parent_rev":
"0c6adbef4d5f4722e2a224c90164f30ec9cf26dd", "commit_rev":
"618fd4f3564ecc43f4f7bff660c22a9dd5fc2309"}

[commit-bot: I haz the power, 2017-06-08 20:11:28]

Description was changed from

==========
[Android Refactor] Merge WebappDataStorage#LAST_USED_UNSET and LAST_USED_INVALID

Having both LAST_USED_UNSET and LAST_USED_INVALID is unnecessary as
- the "last_used" SharedPreference should never be set to LAST_USED_INVALID
- there isn't any logic which checks whether "last_used" is LAST_USED_INVALID

Additionally, this CL renames LAST_USED_INVALID to TIMESTAMP_INVALID as
the getters for several time-based SharedPreferences other than "last_used"
return LAST_USED_INVALID if the preference is unset.

BUG=None
==========

to

==========
[Android Refactor] Merge WebappDataStorage#LAST_USED_UNSET and LAST_USED_INVALID

Having both LAST_USED_UNSET and LAST_USED_INVALID is unnecessary as
- the "last_used" SharedPreference should never be set to LAST_USED_INVALID
- there isn't any logic which checks whether "last_used" is LAST_USED_INVALID

Additionally, this CL renames LAST_USED_INVALID to TIMESTAMP_INVALID as
the getters for several time-based SharedPreferences other than "last_used"
return LAST_USED_INVALID if the preference is unset.

BUG=None

Review-Url: https://codereview.chromium.org/2927723003
Cr-Commit-Position: refs/heads/master@{#478067}
Committed:
https://chromium.googlesource.com/chromium/src/+/618fd4f3564ecc43f4f7bff660c2...
==========

[commit-bot: I haz the power, 2017-06-08 20:11:30]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/618fd4f3564ecc43f4f7bff660c2...

[jbudorick, 2017-06-09 01:24:52]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2928993004/ by jbudorick@chromium.org.

The reason for reverting is: Spec revert due to significantly increased
flakiness in one of the WebApkUpdateManagerTests:
https://bugs.chromium.org/p/chromium/issues/detail?id=731485.