Fix bug in DocumentMarkerController::ShowMarkers()

Fix bug in DocumentMarkerController::ShowMarkers()

I accidentally introduced a bug in DocumentMarkerController::ShowMarkers() in
https://codereview.chromium.org/2820633002 causing it to crash if we have a node
with a DocumentMarkerList for at least one MarkerType but not all MarkerTypes
(this is very common). I hadn't noticed it until just now because this is a
method only used to assist with debugging. This CL fixes the bug.

BUG=

Review-Url: https://codereview.chromium.org/2908593003
Cr-Commit-Position: refs/heads/master@{#474910}
Committed: https://chromium.googlesource.com/chromium/src/+/0cab0229765caa47ee02c482d768ea65f6e24b5d

[rlanday, 2017-05-25 21:59:08]

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

[rlanday, 2017-05-25 21:59:17]

rlanday@chromium.org changed reviewers:
+ xiaochengh@chromium.org, yosin@chromium.org

[commit-bot: I haz the power, 2017-05-25 21:59:42]

Dry run: CQ is trying da patch.

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

[Xiaocheng, 2017-05-25 22:07:34]

lgtm

[commit-bot: I haz the power, 2017-05-26 02:27:19]

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

[commit-bot: I haz the power, 2017-05-26 02:27:20]

Dry run: This issue passed the CQ dry run.

[yosin_UTC9, 2017-05-26 04:43:22]

The CQ bit was checked by yosin@chromium.org

[yosin_UTC9, 2017-05-26 04:43:22]

lgtm

[commit-bot: I haz the power, 2017-05-26 04:43:56]

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, 2017-05-26 04:49:57]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1495773802521800, "parent_rev":
"e7eadd47df235c4a2b583e12e56279022c9bc944", "commit_rev":
"0cab0229765caa47ee02c482d768ea65f6e24b5d"}

[commit-bot: I haz the power, 2017-05-26 04:50:07]

Description was changed from

==========
Fix bug in DocumentMarkerController::ShowMarkers()

I accidentally introduced a bug in DocumentMarkerController::ShowMarkers() in
https://codereview.chromium.org/2820633002 causing it to crash if we have a node
with a DocumentMarkerList for at least one MarkerType but not all MarkerTypes
(this is very common). I hadn't noticed it until just now because this is a
method only used to assist with debugging. This CL fixes the bug.

BUG=
==========

to

==========
Fix bug in DocumentMarkerController::ShowMarkers()

I accidentally introduced a bug in DocumentMarkerController::ShowMarkers() in
https://codereview.chromium.org/2820633002 causing it to crash if we have a node
with a DocumentMarkerList for at least one MarkerType but not all MarkerTypes
(this is very common). I hadn't noticed it until just now because this is a
method only used to assist with debugging. This CL fixes the bug.

BUG=

Review-Url: https://codereview.chromium.org/2908593003
Cr-Commit-Position: refs/heads/master@{#474910}
Committed:
https://chromium.googlesource.com/chromium/src/+/0cab0229765caa47ee02c482d768...
==========

[commit-bot: I haz the power, 2017-05-26 04:50:09]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/0cab0229765caa47ee02c482d768...