Revert of Remove unnecessary interface TelephoneEventHandler

Revert of Remove unnecessary interface TelephoneEventHandler (patchset #3 id:40001 of https://codereview.webrtc.org/2357583002/ )

Reason for revert:
breaks downstream code

Original issue's description:
> Remove unnecessary interface TelephoneEventHandler.
>
> BUG=webrtc:2795
>
> Committed: https://crrev.com/2beb42983ca24e1326a9a7f2c06b3ad740eea2c3
> Cr-Commit-Position: refs/heads/master@{#14346}

TBR=henrik.lundin@webrtc.org,solenberg@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:2795
Committed: https://crrev.com/799a9d017a807cefb62a15a38d81fe2ad16a586a
Cr-Commit-Position: refs/heads/master@{#14348}

[danilchap, 2016-09-22 10:36:11]

The CQ bit was checked by danilchap@webrtc.org

[danilchap, 2016-09-22 10:36:12]

Created Revert of Remove unnecessary interface TelephoneEventHandler

[commit-bot: I haz the power, 2016-09-22 10:36:22]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2016-09-22 10:36:30]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-22 10:36:37]

Description was changed from

==========
Revert of Remove unnecessary interface TelephoneEventHandler (patchset #3
id:40001 of https://codereview.webrtc.org/2357583002/ )

Reason for revert:
breaks downstream code

Original issue's description:
> Remove unnecessary interface TelephoneEventHandler.
> 
> BUG=webrtc:2795
> 
> Committed: https://crrev.com/2beb42983ca24e1326a9a7f2c06b3ad740eea2c3
> Cr-Commit-Position: refs/heads/master@{#14346}

TBR=henrik.lundin@webrtc.org,solenberg@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:2795
==========

to

==========
Revert of Remove unnecessary interface TelephoneEventHandler (patchset #3
id:40001 of https://codereview.webrtc.org/2357583002/ )

Reason for revert:
breaks downstream code

Original issue's description:
> Remove unnecessary interface TelephoneEventHandler.
>
> BUG=webrtc:2795
>
> Committed: https://crrev.com/2beb42983ca24e1326a9a7f2c06b3ad740eea2c3
> Cr-Commit-Position: refs/heads/master@{#14346}

TBR=henrik.lundin@webrtc.org,solenberg@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:2795

Committed: https://crrev.com/799a9d017a807cefb62a15a38d81fe2ad16a586a
Cr-Commit-Position: refs/heads/master@{#14348}
==========

[commit-bot: I haz the power, 2016-09-22 10:36:38]

Patchset 1 (id:??) landed as
https://crrev.com/799a9d017a807cefb62a15a38d81fe2ad16a586a
Cr-Commit-Position: refs/heads/master@{#14348}

[hlundin-webrtc, 2016-09-26 15:17:37]

lgtm