ash: display: Safely delete color calibration data

ash: display: Safely delete color calibration data

Fix a crash due to unsafe iterator usage in the DisplayColorManager
destructor.

BUG=488487
TEST=compile

Committed: https://crrev.com/c0ca01a78f0cce5dff227f7aab0b6f0c1755724d
Cr-Commit-Position: refs/heads/master@{#330252}

[spang, 2015-05-15 22:36:59]

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

[spang, 2015-05-15 22:37:08]

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

[spang, 2015-05-15 22:37:27]

I'm heading out in a minute, can you CQ if approved?

[commit-bot: I haz the power, 2015-05-15 22:37:32]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1127213007/1

[commit-bot: I haz the power, 2015-05-15 23:24:02]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-05-15 23:24:03]

Dry run: This issue passed the CQ dry run.

[oshima, 2015-05-16 00:38:28]

The CQ bit was checked by oshima@chromium.org

[oshima, 2015-05-16 00:38:28]

lgtm

[commit-bot: I haz the power, 2015-05-16 00:40:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1127213007/1

[commit-bot: I haz the power, 2015-05-16 00:46:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-18 11:30:07]

Patchset 1 (id:??) landed as
https://crrev.com/c0ca01a78f0cce5dff227f7aab0b6f0c1755724d
Cr-Commit-Position: refs/heads/master@{#330252}