Fix an Aura crash several minutes into V2Mirroring

Fix an Aura crash several minutes into V2Mirroring

Since we deleted the gfx::screen each time we closed an app,
A query to the screen size during metrics gathering was causing
a check failure.

BUG=

Committed: https://crrev.com/7c0546789b9d1eaf04d57b816847cf18aa5d684e
Cr-Commit-Position: refs/heads/master@{#302194}

[GusFernandez, 2014-10-30 22:08:33]

gusfernandez@chromium.org changed reviewers:
+ gunsch@chromium.org, lcwu@chromium.org

[GusFernandez, 2014-10-30 22:08:47]

Upstreamed changes.

[gunsch, 2014-10-30 22:25:02]

https://codereview.chromium.org/691023003/diff/1/chromecast/browser/cast_brow...
File chromecast/browser/cast_browser_main_parts.cc (right):

https://codereview.chromium.org/691023003/diff/1/chromecast/browser/cast_brow...
chromecast/browser/cast_browser_main_parts.cc:25: #include
"ui/ozone/public/ozone_switches.h"
kIgnoreGpuBlacklist is in content_switches, which is already included

[GusFernandez, 2014-10-30 22:59:54]

https://codereview.chromium.org/691023003/diff/1/chromecast/browser/cast_brow...
File chromecast/browser/cast_browser_main_parts.cc (right):

https://codereview.chromium.org/691023003/diff/1/chromecast/browser/cast_brow...
chromecast/browser/cast_browser_main_parts.cc:25: #include
"ui/ozone/public/ozone_switches.h"
On 2014/10/30 22:25:02, gunsch wrote:
> kIgnoreGpuBlacklist is in content_switches, which is already included

Done.

[gunsch, 2014-10-30 23:00:28]

lgtm

[lcwu1, 2014-10-30 23:04:52]

lgtm

[GusFernandez, 2014-10-30 23:19:57]

The CQ bit was checked by gusfernandez@chromium.org

[commit-bot: I haz the power, 2014-10-30 23:21:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/691023003/40001

[commit-bot: I haz the power, 2014-10-31 00:03:00]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2014-10-31 00:03:30]

Patchset 3 (id:??) landed as
https://crrev.com/7c0546789b9d1eaf04d57b816847cf18aa5d684e
Cr-Commit-Position: refs/heads/master@{#302194}