Remove rtc_peer_connection_handler.cc's OverrideDefaultCertificate

Remove rtc_peer_connection_handler.cc's OverrideDefaultCertificate
which was used to override the default DTLS certificate to use in WebRTC to
ECDSA. This is no longer needed since KT_DEFAULT == KT_ECDSA, meaning ECDSA
is already the default certificate and calling this function does nothing.

BUG=601850, 611698
Committed: https://crrev.com/2c8d51533a9a774650bc2f728cee2c9e97fb70a4
Cr-Commit-Position: refs/heads/master@{#396460}

[hbos_chromium, 2016-05-27 11:44:47]

hbos@chromium.org changed reviewers:
+ tommi@chromium.org

[hbos_chromium, 2016-05-27 11:44:47]

Please take a look, tommi.

[hbos_chromium, 2016-05-27 11:44:55]

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

[commit-bot: I haz the power, 2016-05-27 11:45:07]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2016323002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2016323002/1

[tommi (sloooow) - chröme, 2016-05-27 11:59:32]

lgtm

[hbos_chromium, 2016-05-27 12:12:08]

The CQ bit was checked by hbos@chromium.org

[commit-bot: I haz the power, 2016-05-27 12:12:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2016323002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2016323002/20001

[commit-bot: I haz the power, 2016-05-27 14:13:58]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-05-27 14:15:59]

Description was changed from

==========
Remove rtc_peer_connection_handler.cc's OverrideDefaultCertificate
which was used to override the default DTLS certificate to use in WebRTC to
ECDSA. This is no longer needed since KT_DEFAULT == KT_ECDSA, meaning ECDSA
is already the default certificate and calling this function does nothing.

BUG=601850, 611698
==========

to

==========
Remove rtc_peer_connection_handler.cc's OverrideDefaultCertificate
which was used to override the default DTLS certificate to use in WebRTC to
ECDSA. This is no longer needed since KT_DEFAULT == KT_ECDSA, meaning ECDSA
is already the default certificate and calling this function does nothing.

BUG=601850, 611698

Committed: https://crrev.com/2c8d51533a9a774650bc2f728cee2c9e97fb70a4
Cr-Commit-Position: refs/heads/master@{#396460}
==========

[commit-bot: I haz the power, 2016-05-27 14:16:00]

Patchset 2 (id:??) landed as
https://crrev.com/2c8d51533a9a774650bc2f728cee2c9e97fb70a4
Cr-Commit-Position: refs/heads/master@{#396460}