Convert enable_pre_sync_backup flag to new flags system.

Convert enable_pre_sync_backup flag to new flags system.

This flag's usage is very isolated so is a good candidate for the new system. There is now a generated header for the #define rather than a global define.

Reland of http://crrev.com/1478623004#ps60001
TBR=zea@chromium.org

Committed: https://crrev.com/db7f9756dc6e236589b90c76d6fa0f1244601e78
Cr-Commit-Position: refs/heads/master@{#362365}

[brettw, 2015-12-01 05:02:28]

The CQ bit was checked by brettw@chromium.org to run a CQ dry run

[brettw, 2015-12-01 05:02:29]

Fix

[brettw, 2015-12-01 05:02:57]

Reland, fix is in patch 2 (needed extra dep).

[commit-bot: I haz the power, 2015-12-01 05:03:19]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1487873003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1487873003/20001

[brettw, 2015-12-01 05:28:53]

The CQ bit was unchecked by brettw@chromium.org

[brettw, 2015-12-01 05:28:55]

The CQ bit was checked by brettw@chromium.org

[commit-bot: I haz the power, 2015-12-01 05:29:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1487873003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1487873003/20001

[commit-bot: I haz the power, 2015-12-01 06:54:31]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-12-01 06:55:45]

Description was changed from

==========
Convert enable_pre_sync_backup flag to new flags system.

This flag's usage is very isolated so is a good candidate for the new system.
There is now a generated header for the #define rather than a global define.

Reland of http://crrev.com/1478623004#ps60001
TBR=zea@chromium.org
==========

to

==========
Convert enable_pre_sync_backup flag to new flags system.

This flag's usage is very isolated so is a good candidate for the new system.
There is now a generated header for the #define rather than a global define.

Reland of http://crrev.com/1478623004#ps60001
TBR=zea@chromium.org

Committed: https://crrev.com/db7f9756dc6e236589b90c76d6fa0f1244601e78
Cr-Commit-Position: refs/heads/master@{#362365}
==========

[commit-bot: I haz the power, 2015-12-01 06:55:46]

Patchset 2 (id:??) landed as
https://crrev.com/db7f9756dc6e236589b90c76d6fa0f1244601e78
Cr-Commit-Position: refs/heads/master@{#362365}

[vabr (Chromium), 2015-12-01 09:31:20]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1490713002/ by vabr@chromium.org.

The reason for reverting is: Speculative revert, CrOS compile broken, more info
on the bug.
BUG=563927.