Make Position::FirstPositionInNode() to take const Node& instead of Node*

Make Position::FirstPositionInNode() to take const Node& instead of Node*

This patch makes |Position::FirstPositionInNode()| to take |const Node&| instead
of |Node*| since |Node| parameter can not be nullptr for improving code health.


This patch is a preparation of make |Position| to hold |const Node&|[1] and
similar to the patch[2] which change |BeforeNode()|.

[1] http://crbug.com/735327 Position should hold const Node instead of Node
[2] http://crbug.com/2950053002: Make Position::BeforeNode() to take const Node& 
instead of Node*


BUG=734849
TEST=n/a; no behavior changes

Review-Url: https://codereview.chromium.org/2952983002
Cr-Commit-Position: refs/heads/master@{#481810}
Committed: https://chromium.googlesource.com/chromium/src/+/6987d19cbf857ea5158f967d304b0572048c7199

[yosin_UTC9, 2017-06-22 05:30:49]

Description was changed from

==========
2017-06-22T14:28:55

BUG=734849

2017-06-22T14:28:46
==========

to

==========
Make Position::FirstPositionInNode() to take const Node& instead of Node*

This patch makes |Position::FirstPositionInNode()| to take |const Node&| instead
of |Node*| since |Node| parameter can not be nullptr for improving code health.


This patch is a preparation of make |Position| to hold |const Node&|[1] and
similar to the patch[2] which change |BeforeNode()|.

[1] http://crbug.com/735327 Position should hold const Node instead of Node
[2] http://crbug.com/2950053002: Make Position::BeforeNode() to take const Node&

instead of Node*


BUG=734849
TEST=n/a; no behavior changes
==========

[yosin_UTC9, 2017-06-22 05:31:05]

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

[commit-bot: I haz the power, 2017-06-22 05:31:20]

Dry run: 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, 2017-06-22 06:18:48]

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

[commit-bot: I haz the power, 2017-06-22 06:18:49]

Dry run: Try jobs failed on following builders:
  linux_chromium_chromeos_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[yosin_UTC9, 2017-06-22 07:40:20]

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

[yosin_UTC9, 2017-06-22 07:40:21]

PTAL

[Xiaocheng, 2017-06-22 18:11:51]

lgtm.

Thanks for making this big patch, which needs quite some efforts!

[yosin_UTC9, 2017-06-23 00:49:55]

The CQ bit was checked by yosin@chromium.org

[commit-bot: I haz the power, 2017-06-23 00:50:13]

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, 2017-06-23 00:57:20]

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

[commit-bot: I haz the power, 2017-06-23 00:57:21]

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...)

[yosin_UTC9, 2017-06-23 01:38:55]

The CQ bit was checked by yosin@chromium.org

[yosin_UTC9, 2017-06-23 01:38:55]

The patchset sent to the CQ was uploaded after l-g-t-m from
xiaochengh@chromium.org
Link to the patchset: https://codereview.chromium.org/2952983002/#ps20001
(title: "2017-06-23T10:37:43")

[commit-bot: I haz the power, 2017-06-23 01:39:21]

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, 2017-06-23 05:34:08]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1498181935193790,
"parent_rev": "2ad39770967ebd93314070776ffe92d3eaeb8a6b", "commit_rev":
"6987d19cbf857ea5158f967d304b0572048c7199"}

[commit-bot: I haz the power, 2017-06-23 05:34:21]

Description was changed from

==========
Make Position::FirstPositionInNode() to take const Node& instead of Node*

This patch makes |Position::FirstPositionInNode()| to take |const Node&| instead
of |Node*| since |Node| parameter can not be nullptr for improving code health.


This patch is a preparation of make |Position| to hold |const Node&|[1] and
similar to the patch[2] which change |BeforeNode()|.

[1] http://crbug.com/735327 Position should hold const Node instead of Node
[2] http://crbug.com/2950053002: Make Position::BeforeNode() to take const Node&

instead of Node*


BUG=734849
TEST=n/a; no behavior changes
==========

to

==========
Make Position::FirstPositionInNode() to take const Node& instead of Node*

This patch makes |Position::FirstPositionInNode()| to take |const Node&| instead
of |Node*| since |Node| parameter can not be nullptr for improving code health.


This patch is a preparation of make |Position| to hold |const Node&|[1] and
similar to the patch[2] which change |BeforeNode()|.

[1] http://crbug.com/735327 Position should hold const Node instead of Node
[2] http://crbug.com/2950053002: Make Position::BeforeNode() to take const Node&

instead of Node*


BUG=734849
TEST=n/a; no behavior changes

Review-Url: https://codereview.chromium.org/2952983002
Cr-Commit-Position: refs/heads/master@{#481810}
Committed:
https://chromium.googlesource.com/chromium/src/+/6987d19cbf857ea5158f967d304b...
==========

[commit-bot: I haz the power, 2017-06-23 05:34:28]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/6987d19cbf857ea5158f967d304b...