Don't update the title to about:blank on first show for custom tabs

Don't update the title to about:blank on first show for custom tabs

Currently custom tabs don't show a title if the title is still the url,
but due to optimizations inside warmup(), the title might end up being
about:blank (even if the current url is not about:blank). The domain
explicitly guards against this but title doesn't. Update the title to
also never show about:blank

BUG=579647
Committed: https://crrev.com/0551ff294144d38973bfdf2e01f08aabaaff5b22
Cr-Commit-Position: refs/heads/master@{#371276}

[Yusuf, 2016-01-22 22:07:04]

yusufo@chromium.org changed reviewers:
+ dfalcantara@chromium.org

[gone, 2016-01-25 18:34:28]

lgtm

[Yusuf, 2016-01-25 18:35:29]

The CQ bit was checked by yusufo@chromium.org

[commit-bot: I haz the power, 2016-01-25 18:36:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1614843006/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1614843006/20001

[commit-bot: I haz the power, 2016-01-25 19:23:51]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-01-25 19:26:27]

Description was changed from

==========
Don't update the title to about:blank on first show for custom tabs

Currently custom tabs don't show a title if the title is still the url,
but due to optimizations inside warmup(), the title might end up being
about:blank (even if the current url is not about:blank). The domain
explicitly guards against this but title doesn't. Update the title to
also never show about:blank

BUG=579647
==========

to

==========
Don't update the title to about:blank on first show for custom tabs

Currently custom tabs don't show a title if the title is still the url,
but due to optimizations inside warmup(), the title might end up being
about:blank (even if the current url is not about:blank). The domain
explicitly guards against this but title doesn't. Update the title to
also never show about:blank

BUG=579647

Committed: https://crrev.com/0551ff294144d38973bfdf2e01f08aabaaff5b22
Cr-Commit-Position: refs/heads/master@{#371276}
==========

[commit-bot: I haz the power, 2016-01-25 19:26:28]

Patchset 2 (id:??) landed as
https://crrev.com/0551ff294144d38973bfdf2e01f08aabaaff5b22
Cr-Commit-Position: refs/heads/master@{#371276}