Remove incorrect DCHECK in WebContentsImpl::UpdateTitle.

Remove incorrect DCHECK in WebContentsImpl::UpdateTitle.

This may legitimately fail when replaceState IPCs arrive from a
RenderFrameHost that is pending deletion, causing its nav_entry_id
to be reset.  In this case, we'll find a NavigationEntry by page_id
but not by nav_entry_id.

BUG=638089
TEST=No debug crash going cross process during replaceState flood.

Committed: https://crrev.com/03e1338d8a29ec8a050fc0d47bde5426bf3d8707
Cr-Commit-Position: refs/heads/master@{#422978}

[Charlie Reis, 2016-10-04 05:39:00]

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

[commit-bot: I haz the power, 2016-10-04 05:39:13]

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, 2016-10-04 06:30:21]

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

[commit-bot: I haz the power, 2016-10-04 06:30:22]

Dry run: This issue passed the CQ dry run.

[Charlie Reis, 2016-10-04 18:24:17]

creis@chromium.org changed reviewers:
+ avi@chromium.org

[Charlie Reis, 2016-10-04 18:24:18]

Avi, can you take a look?  This handles the UpdateTitle DCHECK, and I'll do the
NavigateInternal one in a separate CL.

[Avi (use Gerrit), 2016-10-04 22:13:33]

LGTM

[Charlie Reis, 2016-10-04 22:40:55]

The CQ bit was checked by creis@chromium.org

[commit-bot: I haz the power, 2016-10-04 22:41:41]

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, 2016-10-04 22:47:52]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-04 22:50:25]

Description was changed from

==========
Remove incorrect DCHECK in WebContentsImpl::UpdateTitle.

This may legitimately fail when replaceState IPCs arrive from a
RenderFrameHost that is pending deletion, causing its nav_entry_id
to be reset.  In this case, we'll find a NavigationEntry by page_id
but not by nav_entry_id.

BUG=638089
TEST=No debug crash going cross process during replaceState flood.
==========

to

==========
Remove incorrect DCHECK in WebContentsImpl::UpdateTitle.

This may legitimately fail when replaceState IPCs arrive from a
RenderFrameHost that is pending deletion, causing its nav_entry_id
to be reset.  In this case, we'll find a NavigationEntry by page_id
but not by nav_entry_id.

BUG=638089
TEST=No debug crash going cross process during replaceState flood.

Committed: https://crrev.com/03e1338d8a29ec8a050fc0d47bde5426bf3d8707
Cr-Commit-Position: refs/heads/master@{#422978}
==========

[commit-bot: I haz the power, 2016-10-04 22:50:26]

Patchset 1 (id:??) landed as
https://crrev.com/03e1338d8a29ec8a050fc0d47bde5426bf3d8707
Cr-Commit-Position: refs/heads/master@{#422978}