[Ozone-Drm] Revert of holding on to the DRM FDs in the browser process

[Ozone-Drm] Revert of holding on to the DRM FDs in the browser process

Holding on to the DRM FD means we're leaking scanout buffers when the
GPU process crashes.

BUG=487630, 445773
Committed: https://crrev.com/76aab8398aa38b5672d2148d5b1469feddc20502
Cr-Commit-Position: refs/heads/master@{#330125}

[dnicoara, 2015-05-15 14:25:49]

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

[commit-bot: I haz the power, 2015-05-15 14:26:06]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1125283012/1

[dnicoara, 2015-05-15 14:26:34]

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

[commit-bot: I haz the power, 2015-05-15 14:46:42]

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

[commit-bot: I haz the power, 2015-05-15 14:46:43]

Dry run: This issue passed the CQ dry run.

[spang, 2015-05-15 17:38:27]

lgtm

[dnicoara, 2015-05-15 17:39:02]

The CQ bit was checked by dnicoara@chromium.org

[commit-bot: I haz the power, 2015-05-15 17:39:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1125283012/1

[commit-bot: I haz the power, 2015-05-15 17:45:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-15 17:46:04]

Patchset 1 (id:??) landed as
https://crrev.com/76aab8398aa38b5672d2148d5b1469feddc20502
Cr-Commit-Position: refs/heads/master@{#330125}