Fast path for google_util::IsValidHostName

Fast path for google_util::IsValidHostName

IsValidHostName takes a host and tries to match it with
[www.]<domain_in_lower_case>.<TLD>

However, finding valid TLDs entails searching a big DAFSA. This patch
uses a fast path to fail fast if <domain_in_lower_case> is not found in
the input host.

This function was seen in profiles on the IO thread in
variations::AppendVariationHeaders.

BUG=664174
Committed: https://crrev.com/a628b8fc2a3e19ce72cef9cd0802ad79a892f7f6
Cr-Commit-Position: refs/heads/master@{#431995}

[Charlie Harrison, 2016-11-12 07:09:52]

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

[commit-bot: I haz the power, 2016-11-12 07:10:02]

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, 2016-11-12 08:03:02]

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

[commit-bot: I haz the power, 2016-11-12 08:03:03]

Dry run: This issue passed the CQ dry run.

[Charlie Harrison, 2016-11-14 22:13:28]

csharrison@chromium.org changed reviewers:
+ isherman@chromium.org

[Charlie Harrison, 2016-11-14 22:13:28]

isherman, WDYT? I think this fast path will be hit in enough cases that it is
worthwhile to avoid checking the registry controlled domains set.

[Ilya Sherman, 2016-11-14 22:57:50]

LGTM, thanks.

[Charlie Harrison, 2016-11-14 23:03:16]

The CQ bit was checked by csharrison@chromium.org

[commit-bot: I haz the power, 2016-11-14 23:04:45]

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, 2016-11-14 23:59:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-15 00:02:21]

Description was changed from

==========
Fast path for google_util::IsValidHostName

IsValidHostName takes a host and tries to match it with
[www.]<domain_in_lower_case>.<TLD>

However, finding valid TLDs entails searching a big DAFSA. This patch
uses a fast path to fail fast if <domain_in_lower_case> is not found in
the input host.

This function was seen in profiles on the IO thread in
variations::AppendVariationHeaders.

BUG=664174
==========

to

==========
Fast path for google_util::IsValidHostName

IsValidHostName takes a host and tries to match it with
[www.]<domain_in_lower_case>.<TLD>

However, finding valid TLDs entails searching a big DAFSA. This patch
uses a fast path to fail fast if <domain_in_lower_case> is not found in
the input host.

This function was seen in profiles on the IO thread in
variations::AppendVariationHeaders.

BUG=664174

Committed: https://crrev.com/a628b8fc2a3e19ce72cef9cd0802ad79a892f7f6
Cr-Commit-Position: refs/heads/master@{#431995}
==========

[commit-bot: I haz the power, 2016-11-15 00:02:22]

Patchset 1 (id:??) landed as
https://crrev.com/a628b8fc2a3e19ce72cef9cd0802ad79a892f7f6
Cr-Commit-Position: refs/heads/master@{#431995}