Change GetCanonicalSuffix() interface.

Change GetCanonicalSuffix() interface.

This CL changes the argument of GetCanonicalSuffix() from HostPortPair to
std::string (both const&) to better document the fact that GetCanonicalSuffix
only operates on that field.

BUG=392575
Committed: https://crrev.com/c45e09b004eb4fe3f317052c072f6173c1e6986c
Cr-Commit-Position: refs/heads/master@{#314014}

[Bence, 2015-01-30 19:50:51]

bnc@chromium.org changed reviewers:
+ rch@chromium.org

[Bence, 2015-01-30 19:50:51]

Ryan, PTAL.  Thank you.

[Ryan Hamilton, 2015-01-30 21:33:08]

lgtm

Nice catch.

[Bence, 2015-01-30 21:50:45]

The CQ bit was checked by bnc@chromium.org

[commit-bot: I haz the power, 2015-01-30 21:51:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/868753007/1

[commit-bot: I haz the power, 2015-01-30 22:45:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-30 22:46:48]

Patchset 1 (id:??) landed as
https://crrev.com/c45e09b004eb4fe3f317052c072f6173c1e6986c
Cr-Commit-Position: refs/heads/master@{#314014}