ozone: drm: Fix graphics buffer handle leak in DrmConsoleBuffer

ozone: drm: Fix graphics buffer handle leak in DrmConsoleBuffer

We are leaking graphics buffer handles every time we plug in a display.
The handle is created by DRM_IOCTL_MODE_GETFB. This adds a call to
DRM_IOCTL_GEM_CLOSE to release the handle.

BUG=470772
TEST=plug & unplug HDMI repeatedly. No significant increase in shared
  memory usage over time (as reported by "free" command).

Committed: https://crrev.com/756bbb93152e169e92e5e21b82ba724dac2f1822
Cr-Commit-Position: refs/heads/master@{#325769}

[spang, 2015-04-18 01:33:58]

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

[spang, 2015-04-18 01:33:58]

I'm stumped as to why this code is running every time a monitor gets plugged in
- isn't it just for internal display on boot?

Anyway, this plugs the leak.

[marcheu, 2015-04-18 02:15:13]

lgtm

[spang, 2015-04-18 02:15:47]

The CQ bit was checked by spang@chromium.org

[commit-bot: I haz the power, 2015-04-18 02:16:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1080923006/20001

[commit-bot: I haz the power, 2015-04-18 02:40:47]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-04-18 02:41:34]

Patchset 2 (id:??) landed as
https://crrev.com/756bbb93152e169e92e5e21b82ba724dac2f1822
Cr-Commit-Position: refs/heads/master@{#325769}

[dnicoara, 2015-04-20 13:39:17]

On 2015/04/18 01:33:58, spang wrote:
> I'm stumped as to why this code is running every time a monitor gets plugged
in
> - isn't it just for internal display on boot?
> 
> Anyway, this plugs the leak.

It isn't necessarily the internal display. It is the display showing the boot
splash. Also the concept of "on boot" is hard to figure out.