Revert of If SRTP sessions exist, don't create new ones when applying answer.

Revert of If SRTP sessions exist, don't create new ones when applying answer. (patchset #1 id:1 of https://codereview.webrtc.org/3019443002/ )

Reason for revert:
Speculative revert since all Android bots on WebRTC FYI started to fail when this CL landed.

https://build.chromium.org/p/chromium.webrtc.fyi/builders/Android%20Tests%20%28dbg%29%20%28L%20Nexus6%29

Original issue's description:
> If SRTP sessions exist, don't create new ones when applying answer.
> 
> Instead, call the "Update" methods of SrtpSession, which will just call
> srtp_update, instead of wiping out the session state completely.
> 
> This was causing decryption to stop working when subsequent
> offers/answers are applied. We don't know enough about SRTP to
> understand the root cause, and I wasn't able to write an integration
> test that reproduces the issue... But at least this fixes the bug that
> can be reproduced reliably using Hangouts.
> 
> BUG=webrtc:8251
> 
> Review-Url: https://codereview.webrtc.org/3019443002
> Cr-Commit-Position: refs/heads/master@{#19874}
> Committed: https://webrtc.googlesource.com/src/+/5ada7acf603e90e71990e9d4ff8f49389f24958c

TBR=zhihuang@webrtc.org,deadbeef@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:8251
NOTRY=TRUE

Review-Url: https://codereview.webrtc.org/3017543002
Cr-Commit-Position: refs/heads/master@{#19882}
Committed: https://webrtc.googlesource.com/src/+/1d4db392c71595f05a5258e16734ff3ec446c115

[henrika_webrtc, 2017-09-18 09:16:54]

The CQ bit was checked by henrika@webrtc.org

[henrika_webrtc, 2017-09-18 09:16:55]

Created Revert of If SRTP sessions exist, don't create new ones when applying
answer.

[commit-bot: I haz the power, 2017-09-18 09:17:05]

CQ is trying da patch.

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

[henrika_webrtc, 2017-09-18 09:29:37]

The CQ bit was unchecked by henrika@webrtc.org

[henrika_webrtc, 2017-09-18 09:29:53]

Description was changed from

==========
Revert of If SRTP sessions exist, don't create new ones when applying answer.
(patchset #1 id:1 of https://codereview.webrtc.org/3019443002/ )

Reason for revert:
Speculative revert since all Android bots on WebRTC FYI started to fail when
this CL landed.

https://build.chromium.org/p/chromium.webrtc.fyi/builders/Android%20Tests%20%...

Original issue's description:
> If SRTP sessions exist, don't create new ones when applying answer.
> 
> Instead, call the "Update" methods of SrtpSession, which will just call
> srtp_update, instead of wiping out the session state completely.
> 
> This was causing decryption to stop working when subsequent
> offers/answers are applied. We don't know enough about SRTP to
> understand the root cause, and I wasn't able to write an integration
> test that reproduces the issue... But at least this fixes the bug that
> can be reproduced reliably using Hangouts.
> 
> BUG=webrtc:8251
> 
> Review-Url: https://codereview.webrtc.org/3019443002
> Cr-Commit-Position: refs/heads/master@{#19874}
> Committed:
https://webrtc.googlesource.com/src/+/5ada7acf603e90e71990e9d4ff8f49389f24958c

TBR=zhihuang@webrtc.org,deadbeef@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:8251
==========

to

==========
Revert of If SRTP sessions exist, don't create new ones when applying answer.
(patchset #1 id:1 of https://codereview.webrtc.org/3019443002/ )

Reason for revert:
Speculative revert since all Android bots on WebRTC FYI started to fail when
this CL landed.

https://build.chromium.org/p/chromium.webrtc.fyi/builders/Android%20Tests%20%...

Original issue's description:
> If SRTP sessions exist, don't create new ones when applying answer.
> 
> Instead, call the "Update" methods of SrtpSession, which will just call
> srtp_update, instead of wiping out the session state completely.
> 
> This was causing decryption to stop working when subsequent
> offers/answers are applied. We don't know enough about SRTP to
> understand the root cause, and I wasn't able to write an integration
> test that reproduces the issue... But at least this fixes the bug that
> can be reproduced reliably using Hangouts.
> 
> BUG=webrtc:8251
> 
> Review-Url: https://codereview.webrtc.org/3019443002
> Cr-Commit-Position: refs/heads/master@{#19874}
> Committed:
https://webrtc.googlesource.com/src/+/5ada7acf603e90e71990e9d4ff8f49389f24958c

TBR=zhihuang@webrtc.org,deadbeef@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:8251
NOTRY=TRUE
==========

[henrika_webrtc, 2017-09-18 09:30:11]

The CQ bit was checked by henrika@webrtc.org

[commit-bot: I haz the power, 2017-09-18 09:30:15]

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, 2017-09-18 09:34:31]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1505727011583400, "parent_rev":
"9a2e906b0c06ee1a9b75c734bf58326469db8e93", "commit_rev":
"1d4db392c71595f05a5258e16734ff3ec446c115"}

[commit-bot: I haz the power, 2017-09-18 09:34:35]

Description was changed from

==========
Revert of If SRTP sessions exist, don't create new ones when applying answer.
(patchset #1 id:1 of https://codereview.webrtc.org/3019443002/ )

Reason for revert:
Speculative revert since all Android bots on WebRTC FYI started to fail when
this CL landed.

https://build.chromium.org/p/chromium.webrtc.fyi/builders/Android%20Tests%20%...

Original issue's description:
> If SRTP sessions exist, don't create new ones when applying answer.
> 
> Instead, call the "Update" methods of SrtpSession, which will just call
> srtp_update, instead of wiping out the session state completely.
> 
> This was causing decryption to stop working when subsequent
> offers/answers are applied. We don't know enough about SRTP to
> understand the root cause, and I wasn't able to write an integration
> test that reproduces the issue... But at least this fixes the bug that
> can be reproduced reliably using Hangouts.
> 
> BUG=webrtc:8251
> 
> Review-Url: https://codereview.webrtc.org/3019443002
> Cr-Commit-Position: refs/heads/master@{#19874}
> Committed:
https://webrtc.googlesource.com/src/+/5ada7acf603e90e71990e9d4ff8f49389f24958c

TBR=zhihuang@webrtc.org,deadbeef@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:8251
NOTRY=TRUE
==========

to

==========
Revert of If SRTP sessions exist, don't create new ones when applying answer.
(patchset #1 id:1 of https://codereview.webrtc.org/3019443002/ )

Reason for revert:
Speculative revert since all Android bots on WebRTC FYI started to fail when
this CL landed.

https://build.chromium.org/p/chromium.webrtc.fyi/builders/Android%20Tests%20%...

Original issue's description:
> If SRTP sessions exist, don't create new ones when applying answer.
> 
> Instead, call the "Update" methods of SrtpSession, which will just call
> srtp_update, instead of wiping out the session state completely.
> 
> This was causing decryption to stop working when subsequent
> offers/answers are applied. We don't know enough about SRTP to
> understand the root cause, and I wasn't able to write an integration
> test that reproduces the issue... But at least this fixes the bug that
> can be reproduced reliably using Hangouts.
> 
> BUG=webrtc:8251
> 
> Review-Url: https://codereview.webrtc.org/3019443002
> Cr-Commit-Position: refs/heads/master@{#19874}
> Committed:
https://webrtc.googlesource.com/src/+/5ada7acf603e90e71990e9d4ff8f49389f24958c

TBR=zhihuang@webrtc.org,deadbeef@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:8251
NOTRY=TRUE

Review-Url: https://codereview.webrtc.org/3017543002
Cr-Commit-Position: refs/heads/master@{#19882}
Committed:
https://webrtc.googlesource.com/src/+/1d4db392c71595f05a5258e16734ff3ec446c115
==========

[commit-bot: I haz the power, 2017-09-18 09:34:36]

Committed patchset #1 (id:1) as
https://webrtc.googlesource.com/src/+/1d4db392c71595f05a5258e16734ff3ec446c115