Cleanup: Pass std::string as const reference from testing/

Cleanup: Pass std::string as const reference from testing/

Passing std::string by reference can prevent extra copying of object.

BUG=367418
TEST=
R=phajdan.jr@chromium.org

Committed: https://crrev.com/a690281b4838171d8391e0804e3354a857fb28e1
Cr-Commit-Position: refs/heads/master@{#396030}

[Paweł Hajdan Jr., 2016-05-25 19:44:13]

LGTM

[ki.stfu, 2016-05-25 21:20:02]

The CQ bit was checked by ki.stfu@gmail.com

[commit-bot: I haz the power, 2016-05-25 21:21:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2001093008/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2001093008/1

[commit-bot: I haz the power, 2016-05-25 23:07:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-25 23:08:23]

Description was changed from

==========
Cleanup: Pass std::string as const reference from testing/

Passing std::string by reference can prevent extra copying of object.

BUG=367418
TEST=
R=phajdan.jr@chromium.org
==========

to

==========
Cleanup: Pass std::string as const reference from testing/

Passing std::string by reference can prevent extra copying of object.

BUG=367418
TEST=
R=phajdan.jr@chromium.org

Committed: https://crrev.com/a690281b4838171d8391e0804e3354a857fb28e1
Cr-Commit-Position: refs/heads/master@{#396030}
==========

[commit-bot: I haz the power, 2016-05-25 23:08:24]

Patchset 1 (id:??) landed as
https://crrev.com/a690281b4838171d8391e0804e3354a857fb28e1
Cr-Commit-Position: refs/heads/master@{#396030}