fix a layout test crash due to no browser window

fix a layout test crash due to no browser window

The test opens a link to a pdf, which results in a download and closing the
tab immediately.
As a result, the crash could triggered by potential race between shut down the
content shell and opening the download.

BUG=707599
Review-Url: https://codereview.chromium.org/2842023003
Cr-Commit-Position: refs/heads/master@{#467392}
Committed: https://chromium.googlesource.com/chromium/src/+/58a9ac7a9f534ef3cda229da75cff9e6f6487a24

[qinmin, 2017-04-25 22:19:13]

qinmin@chromium.org changed reviewers:
+ dtrainor@chromium.org

[qinmin, 2017-04-25 22:19:23]

PTAL

[David Trainor- moved to gerrit, 2017-04-25 23:31:35]

lgtm

[qinmin, 2017-04-25 23:51:53]

The CQ bit was checked by qinmin@chromium.org

[commit-bot: I haz the power, 2017-04-25 23:52:28]

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, 2017-04-26 00:03:27]

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

[commit-bot: I haz the power, 2017-04-26 00:03:29]

Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[qinmin, 2017-04-26 17:41:15]

qinmin@chromium.org changed reviewers:
+ mkwst@chromium.org

[qinmin, 2017-04-26 17:41:15]

+mkwst@ for OWNER

[Mike West, 2017-04-26 17:43:00]

lgtm

[qinmin, 2017-04-26 18:34:39]

The CQ bit was checked by qinmin@chromium.org

[commit-bot: I haz the power, 2017-04-26 18:35:37]

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, 2017-04-26 18:45:06]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493231679293710, "parent_rev":
"5ea78625e749782bff7e8009a66f90afa850ffbb", "commit_rev":
"58a9ac7a9f534ef3cda229da75cff9e6f6487a24"}

[commit-bot: I haz the power, 2017-04-26 18:46:18]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493231679293710, "parent_rev":
"5ea78625e749782bff7e8009a66f90afa850ffbb", "commit_rev":
"58a9ac7a9f534ef3cda229da75cff9e6f6487a24"}

[commit-bot: I haz the power, 2017-04-26 18:46:21]

Description was changed from

==========
fix a layout test crash due to no browser window

The test opens a link to a pdf, which results in a download and closing the
tab immediately.
As a result, the crash could triggered by potential race between shut down the
content shell and opening the download.

BUG=707599
==========

to

==========
fix a layout test crash due to no browser window

The test opens a link to a pdf, which results in a download and closing the
tab immediately.
As a result, the crash could triggered by potential race between shut down the
content shell and opening the download.

BUG=707599

Review-Url: https://codereview.chromium.org/2842023003
Cr-Commit-Position: refs/heads/master@{#467392}
Committed:
https://chromium.googlesource.com/chromium/src/+/58a9ac7a9f534ef3cda229da75cf...
==========

[commit-bot: I haz the power, 2017-04-26 18:46:22]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/58a9ac7a9f534ef3cda229da75cf...