[Layout API] Fix layoutViewItem() null check in Element.cpp

[Layout API] Fix layoutViewItem() null check in Element.cpp

There are two instances where we are creating a LayoutViewItem and
incorrectly checking whether the underlying layout view is null. At
this stage of the block layout API, the correct way is to call the
isNull() method; checking whether the layoutViewItem object itself
is null does not tell you whether the underlying layout view is null.

BUG=499321
Committed: https://crrev.com/9e932c6f79609ca3163b40212835d37e8ff1a779
Cr-Commit-Position: refs/heads/master@{#405645}

[pilgrim_google, 2016-07-14 20:08:12]

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

[commit-bot: I haz the power, 2016-07-14 20:08:37]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[pilgrim_google, 2016-07-14 20:08:50]

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

[eae, 2016-07-14 22:02:46]

OK, LGTM

[commit-bot: I haz the power, 2016-07-14 22:21:45]

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

[commit-bot: I haz the power, 2016-07-14 22:21:45]

Dry run: This issue passed the CQ dry run.

[pilgrim_google, 2016-07-15 00:09:34]

The CQ bit was checked by pilgrim@chromium.org

[commit-bot: I haz the power, 2016-07-15 00:10:03]

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, 2016-07-15 00:15:52]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-07-15 00:15:55]

CQ bit was unchecked.

[commit-bot: I haz the power, 2016-07-15 00:17:54]

Description was changed from

==========
[Layout API] Fix layoutViewItem() null check in Element.cpp

There are two instances where we are creating a LayoutViewItem and
incorrectly checking whether the underlying layout view is null. At
this stage of the block layout API, the correct way is to call the
isNull() method; checking whether the layoutViewItem object itself
is null does not tell you whether the underlying layout view is null.

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

to

==========
[Layout API] Fix layoutViewItem() null check in Element.cpp

There are two instances where we are creating a LayoutViewItem and
incorrectly checking whether the underlying layout view is null. At
this stage of the block layout API, the correct way is to call the
isNull() method; checking whether the layoutViewItem object itself
is null does not tell you whether the underlying layout view is null.

BUG=499321

Committed: https://crrev.com/9e932c6f79609ca3163b40212835d37e8ff1a779
Cr-Commit-Position: refs/heads/master@{#405645}
==========

[commit-bot: I haz the power, 2016-07-15 00:17:55]

Patchset 1 (id:??) landed as
https://crrev.com/9e932c6f79609ca3163b40212835d37e8ff1a779
Cr-Commit-Position: refs/heads/master@{#405645}