[Layout API] Convert ViewportScrollCallback to use Document::layoutViewItem()

[Layout API] Convert ViewportScrollCallback to use Document::layoutViewItem()

There were several references to Document::layoutView()
which is deprecated by the new layout API. I converted them to use
layoutViewItem() instead. No new API methods were required.

There are no functional changes.

BUG=499321
Committed: https://crrev.com/e3a4314bf9806e94ff93337a7db43c932039427b
Cr-Commit-Position: refs/heads/master@{#389911}

[pilgrim_google, 2016-04-26 18:57:16]

pilgrim@chromium.org changed reviewers:
+ eae@chromium.org, jsbell@chromium.org, leviw@chromium.org

[leviw_travelin_and_unemployed, 2016-04-26 20:38:43]

The CQ bit was checked by leviw@chromium.org

[leviw_travelin_and_unemployed, 2016-04-26 20:38:43]

lgtm

[commit-bot: I haz the power, 2016-04-26 20:39:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1923533003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1923533003/1

[commit-bot: I haz the power, 2016-04-26 22:04:54]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-26 22:07:38]

Description was changed from

==========
[Layout API] Convert ViewportScrollCallback to use Document::layoutViewItem()

There were several references to Document::layoutView()
which is deprecated by the new layout API. I converted them to use
layoutViewItem() instead. No new API methods were required.

There are no functional changes.

BUG=499321
==========

to

==========
[Layout API] Convert ViewportScrollCallback to use Document::layoutViewItem()

There were several references to Document::layoutView()
which is deprecated by the new layout API. I converted them to use
layoutViewItem() instead. No new API methods were required.

There are no functional changes.

BUG=499321

Committed: https://crrev.com/e3a4314bf9806e94ff93337a7db43c932039427b
Cr-Commit-Position: refs/heads/master@{#389911}
==========

[commit-bot: I haz the power, 2016-04-26 22:07:40]

Patchset 1 (id:??) landed as
https://crrev.com/e3a4314bf9806e94ff93337a7db43c932039427b
Cr-Commit-Position: refs/heads/master@{#389911}