check if webcontents are available at tabs_api

check if webcontents are available at tabs_api

Everywhere else access to webcontents via tab_strip->GetWebContentsAt(i)
is checked. Missing check here may lead to crash in rare cases.

R=benwells@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2839403005
Cr-Commit-Position: refs/heads/master@{#468577}
Committed: https://chromium.googlesource.com/chromium/src/+/3bab4c6795d212364941d58d6c46af4783622fbe

[benwells, 2017-05-01 23:04:56]

lgtm

[Ilya Tskhay, 2017-05-02 06:33:12]

The CQ bit was checked by i-ts@yandex-team.ru

[commit-bot: I haz the power, 2017-05-02 06:33:30]

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, 2017-05-02 07:15:59]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493706792569150, "parent_rev":
"e588d5c7e3c93b48d11312ea90be5d0ba23193f0", "commit_rev":
"3bab4c6795d212364941d58d6c46af4783622fbe"}

[commit-bot: I haz the power, 2017-05-02 07:16:09]

Description was changed from

==========
check if webcontents are available at tabs_api

Everywhere else access to webcontents via tab_strip->GetWebContentsAt(i)
is checked. Missing check here may lead to crash in rare cases.

R=benwells@chromium.org
BUG=
==========

to

==========
check if webcontents are available at tabs_api

Everywhere else access to webcontents via tab_strip->GetWebContentsAt(i)
is checked. Missing check here may lead to crash in rare cases.

R=benwells@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2839403005
Cr-Commit-Position: refs/heads/master@{#468577}
Committed:
https://chromium.googlesource.com/chromium/src/+/3bab4c6795d212364941d58d6c46...
==========

[commit-bot: I haz the power, 2017-05-02 07:16:10]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/3bab4c6795d212364941d58d6c46...