chromeos: Don't apply stale display power state after resume

chromeos: Don't apply stale display power state after resume

Fix an issue where the last-requested display power state
was bound to a delayed task on resume. If a new state was
requested while the task was waiting to run (e.g. due to
exiting docked mode), the task would later restore the old
state.

Instead, add a thunk for the task that always uses the
currently-requested state.

BUG=chrome-os-partner:32393
Committed: https://crrev.com/c8052f9d1d76ecf5c616558b59913e4f4e59adc6
Cr-Commit-Position: refs/heads/master@{#299812}

[Daniel Erat, 2014-10-13 23:49:14]

(this still needs a test, but i'll wait until i hear that it fixes the bug to
add that.)

[Daniel Erat, 2014-10-15 21:56:54]

derat@chromium.org changed reviewers:
+ oshima@chromium.org

[Daniel Erat, 2014-10-15 21:56:54]

oshima, do you mind reviewing this since dnicoara is out?

[oshima, 2014-10-15 23:11:28]

lgtm

[Daniel Erat, 2014-10-15 23:12:05]

The CQ bit was checked by derat@chromium.org

[commit-bot: I haz the power, 2014-10-15 23:13:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/652073002/20001

[commit-bot: I haz the power, 2014-10-16 01:47:11]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-10-16 01:48:13]

Patchset 2 (id:??) landed as
https://crrev.com/c8052f9d1d76ecf5c616558b59913e4f4e59adc6
Cr-Commit-Position: refs/heads/master@{#299812}