Fix PointerLockBrowserTest on Mac.

Fix PointerLockBrowserTest on Mac.

The RenderWidgetHostViewMac can outlive its RenderWidgetHost, so we need
to check if the RenderWidgetHost is alive before dereferencing it.

BUG=none

Review-Url: https://codereview.chromium.org/2768263005
Cr-Commit-Position: refs/heads/master@{#459428}
Committed: https://chromium.googlesource.com/chromium/src/+/de6f0d1f3eb6f136533d62cb107c36223374ee3d

[lfg, 2017-03-24 13:51:27]

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

[commit-bot: I haz the power, 2017-03-24 13:51:38]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[lfg, 2017-03-24 13:52:42]

lfg@chromium.org changed reviewers:
+ avi@chromium.org

[lfg, 2017-03-24 13:52:42]

Avi, please take a look.

[commit-bot: I haz the power, 2017-03-24 14:37:18]

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

[commit-bot: I haz the power, 2017-03-24 14:37:18]

Dry run: This issue passed the CQ dry run.

[Avi (use Gerrit), 2017-03-24 15:19:44]

lgtm

[lfg, 2017-03-24 15:24:25]

The CQ bit was checked by lfg@chromium.org

[commit-bot: I haz the power, 2017-03-24 15:25:19]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-24 15:29:59]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1490369065533220, "parent_rev":
"cfae8b4f4c4396c85d3afbc62501460ea3a712fc", "commit_rev":
"de6f0d1f3eb6f136533d62cb107c36223374ee3d"}

[commit-bot: I haz the power, 2017-03-24 15:30:48]

Description was changed from

==========
Fix PointerLockBrowserTest on Mac.

The RenderWidgetHostViewMac can outlive its RenderWidgetHost, so we need
to check if the RenderWidgetHost is alive before dereferencing it.

BUG=none
==========

to

==========
Fix PointerLockBrowserTest on Mac.

The RenderWidgetHostViewMac can outlive its RenderWidgetHost, so we need
to check if the RenderWidgetHost is alive before dereferencing it.

BUG=none

Review-Url: https://codereview.chromium.org/2768263005
Cr-Commit-Position: refs/heads/master@{#459428}
Committed:
https://chromium.googlesource.com/chromium/src/+/de6f0d1f3eb6f136533d62cb107c...
==========

[commit-bot: I haz the power, 2017-03-24 15:30:52]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/de6f0d1f3eb6f136533d62cb107c...