Revert of Completed the functionalities of SrtpTransport.

Revert of Completed the functionalities of SrtpTransport. (patchset 7 id:320001 of https://codereview.webrtc.org/2997983002/ )

Reason for revert:
This seems to be causing some video freezes. See https://bugs.chromium.org/p/webrtc/issues/detail?id=8251

Original issue's description:
> Completed the functionalities of SrtpTransport.
>
> The SrtpTransport takes the SRTP responsibilities from the BaseChannel
> and SrtpFilter. SrtpTransport is now responsible for setting the crypto
> keys, protecting and unprotecting the packets. SrtpTransport doesn't know
> if the keys are from SDES or DTLS handshake.
>
> BaseChannel is now only responsible setting the offer/answer for SDES
> or extracting the key from DtlsTransport and configuring the
> SrtpTransport.
>
> SrtpFilter is used by BaseChannel as a helper for SDES negotiation.
>
> BUG=webrtc:7013
>
> Review-Url: https://codereview.webrtc.org/2997983002
> Cr-Commit-Position: refs/heads/master@{#19636}
> Committed: https://chromium.googlesource.com/external/webrtc/+/e683c6871fef24d3ff64f085d6bc0e965f17fcf7

TBR=deadbeef@webrtc.org,pthatcher@google.com,zhihuang@webrtc.org
Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:7013
Review-Url: https://codereview.webrtc.org/3018513002
Cr-Commit-Position: refs/heads/master@{#19895}
Committed: https://webrtc.googlesource.com/src/+/eb23e1779822ef34df5f62903e19741b76cafdb9

[Zhi Huang, 2017-09-15 18:59:05]

The CQ bit was checked by zhihuang@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2017-09-15 18:59:12]

Dry run: CQ is trying da patch.

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

[Zhi Huang, 2017-09-15 19:01:55]

Description was changed from

==========
Revert of Completed the functionalities of SrtpTransport. (patchset 7 id:320001
of https://codereview.webrtc.org/2997983002/ )

Reason for revert:
This seems to be causing some video freezes. See
https://bugs.chromium.org/p/webrtc/issues/detail?id=8251

Original issue's description:
> Completed the functionalities of SrtpTransport.
>
> The SrtpTransport takes the SRTP responsibilities from the BaseChannel
> and SrtpFilter. SrtpTransport is now responsible for setting the crypto
> keys, protecting and unprotecting the packets. SrtpTransport doesn't know
> if the keys are from SDES or DTLS handshake.
>
> BaseChannel is now only responsible setting the offer/answer for SDES
> or extracting the key from DtlsTransport and configuring the
> SrtpTransport.
>
> SrtpFilter is used by BaseChannel as a helper for SDES negotiation.
>
> BUG=webrtc:7013
>
> Review-Url: https://codereview.webrtc.org/2997983002
> Cr-Commit-Position: refs/heads/master@{#19636}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/e683c6871fef24d3ff64f085d...

TBR=deadbeef@webrtc.org,pthatcher@google.com,zhihuang@webrtc.org
Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:7013
==========

to

==========
Revert of Completed the functionalities of SrtpTransport. (patchset 7 id:320001
of https://codereview.webrtc.org/2997983002/ )

Reason for revert:
This seems to be causing some video freezes. See
https://bugs.chromium.org/p/webrtc/issues/detail?id=8251

Original issue's description:
> Completed the functionalities of SrtpTransport.
>
> The SrtpTransport takes the SRTP responsibilities from the BaseChannel
> and SrtpFilter. SrtpTransport is now responsible for setting the crypto
> keys, protecting and unprotecting the packets. SrtpTransport doesn't know
> if the keys are from SDES or DTLS handshake.
>
> BaseChannel is now only responsible setting the offer/answer for SDES
> or extracting the key from DtlsTransport and configuring the
> SrtpTransport.
>
> SrtpFilter is used by BaseChannel as a helper for SDES negotiation.
>
> BUG=webrtc:7013
>
> Review-Url: https://codereview.webrtc.org/2997983002
> Cr-Commit-Position: refs/heads/master@{#19636}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/e683c6871fef24d3ff64f085d...

TBR=deadbeef@webrtc.org,pthatcher@google.com,zhihuang@webrtc.org
Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:7013
==========

[commit-bot: I haz the power, 2017-09-15 21:09:02]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-09-15 21:09:03]

Dry run: This issue passed the CQ dry run.

[Zhi Huang, 2017-09-19 07:37:27]

The CQ bit was checked by zhihuang@webrtc.org

[commit-bot: I haz the power, 2017-09-19 07:37:42]

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, 2017-09-19 08:12:53]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1505806647840260, "parent_rev":
"25724047892db5bc6b1f5bb0af46886152a46bda", "commit_rev":
"eb23e1779822ef34df5f62903e19741b76cafdb9"}

[commit-bot: I haz the power, 2017-09-19 08:12:57]

Description was changed from

==========
Revert of Completed the functionalities of SrtpTransport. (patchset 7 id:320001
of https://codereview.webrtc.org/2997983002/ )

Reason for revert:
This seems to be causing some video freezes. See
https://bugs.chromium.org/p/webrtc/issues/detail?id=8251

Original issue's description:
> Completed the functionalities of SrtpTransport.
>
> The SrtpTransport takes the SRTP responsibilities from the BaseChannel
> and SrtpFilter. SrtpTransport is now responsible for setting the crypto
> keys, protecting and unprotecting the packets. SrtpTransport doesn't know
> if the keys are from SDES or DTLS handshake.
>
> BaseChannel is now only responsible setting the offer/answer for SDES
> or extracting the key from DtlsTransport and configuring the
> SrtpTransport.
>
> SrtpFilter is used by BaseChannel as a helper for SDES negotiation.
>
> BUG=webrtc:7013
>
> Review-Url: https://codereview.webrtc.org/2997983002
> Cr-Commit-Position: refs/heads/master@{#19636}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/e683c6871fef24d3ff64f085d...

TBR=deadbeef@webrtc.org,pthatcher@google.com,zhihuang@webrtc.org
Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:7013
==========

to

==========
Revert of Completed the functionalities of SrtpTransport. (patchset 7 id:320001
of https://codereview.webrtc.org/2997983002/ )

Reason for revert:
This seems to be causing some video freezes. See
https://bugs.chromium.org/p/webrtc/issues/detail?id=8251

Original issue's description:
> Completed the functionalities of SrtpTransport.
>
> The SrtpTransport takes the SRTP responsibilities from the BaseChannel
> and SrtpFilter. SrtpTransport is now responsible for setting the crypto
> keys, protecting and unprotecting the packets. SrtpTransport doesn't know
> if the keys are from SDES or DTLS handshake.
>
> BaseChannel is now only responsible setting the offer/answer for SDES
> or extracting the key from DtlsTransport and configuring the
> SrtpTransport.
>
> SrtpFilter is used by BaseChannel as a helper for SDES negotiation.
>
> BUG=webrtc:7013
>
> Review-Url: https://codereview.webrtc.org/2997983002
> Cr-Commit-Position: refs/heads/master@{#19636}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/e683c6871fef24d3ff64f085d...

TBR=deadbeef@webrtc.org,pthatcher@google.com,zhihuang@webrtc.org
Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:7013

Review-Url: https://codereview.webrtc.org/3018513002
Cr-Commit-Position: refs/heads/master@{#19895}
Committed:
https://webrtc.googlesource.com/src/+/eb23e1779822ef34df5f62903e19741b76cafdb9
==========

[commit-bot: I haz the power, 2017-09-19 08:12:58]

Committed patchset #1 (id:1) as
https://webrtc.googlesource.com/src/+/eb23e1779822ef34df5f62903e19741b76cafdb9