Removed dead code from NavigationManagerImpl::GetIndexForOffset.

Removed dead code from NavigationManagerImpl::GetIndexForOffset.

If pending item exists and pending index == -1, then last committed item is
always the last one and forward navigation is not possible anyway. 

BUG=661858
Review-Url: https://codereview.chromium.org/2775893003
Cr-Commit-Position: refs/heads/master@{#460559}
Committed: https://chromium.googlesource.com/chromium/src/+/4e7d0d74049c9a5fc567355ea59510a323b2538a

[Eugene But (OOO till 7-30), 2017-03-27 15:46:18]

Description was changed from

==========
Removed dead code from NavigationManagerImpl::GetIndexForOffset.

BUG=661858
==========

to

==========
Removed dead code from NavigationManagerImpl::GetIndexForOffset.

If pending item exists and pending index == -1, then last committed item is
always the last one and forward navigation is not possible anyway. 

BUG=661858
==========

[Eugene But (OOO till 7-30), 2017-03-27 17:24:45]

eugenebut@chromium.org changed reviewers:
+ kkhorimoto@chromium.org

[kkhorimoto, 2017-03-29 00:41:47]

lgtm

[Eugene But (OOO till 7-30), 2017-03-29 21:02:42]

The CQ bit was checked by eugenebut@chromium.org

[commit-bot: I haz the power, 2017-03-29 21:03:50]

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, 2017-03-29 22:47:27]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1490821362190600,
"parent_rev": "b6d4321b17cea01782056a317aeb781367921531", "commit_rev":
"4e7d0d74049c9a5fc567355ea59510a323b2538a"}

[commit-bot: I haz the power, 2017-03-29 22:49:03]

Description was changed from

==========
Removed dead code from NavigationManagerImpl::GetIndexForOffset.

If pending item exists and pending index == -1, then last committed item is
always the last one and forward navigation is not possible anyway. 

BUG=661858
==========

to

==========
Removed dead code from NavigationManagerImpl::GetIndexForOffset.

If pending item exists and pending index == -1, then last committed item is
always the last one and forward navigation is not possible anyway. 

BUG=661858

Review-Url: https://codereview.chromium.org/2775893003
Cr-Commit-Position: refs/heads/master@{#460559}
Committed:
https://chromium.googlesource.com/chromium/src/+/4e7d0d74049c9a5fc567355ea595...
==========

[commit-bot: I haz the power, 2017-03-29 22:49:04]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/4e7d0d74049c9a5fc567355ea595...