Remove global list of SRTP sessions.

Remove global list of SRTP sessions.
Instead save a reference to the SrtpSession inside the srtp_ctx_t.

BUG=webrtc:5133
Committed: https://crrev.com/9cafd972779ed7b25886ab276e0ede7b7a8b76a1
Cr-Commit-Position: refs/heads/master@{#10591}

[juberti, 2015-11-10 01:25:58]

juberti@google.com changed reviewers:
+ juberti@google.com

[juberti, 2015-11-10 01:25:59]

lgtm with comment

https://codereview.webrtc.org/1416093010/diff/1/talk/session/media/srtpfilter.cc
File talk/session/media/srtpfilter.cc (right):

https://codereview.webrtc.org/1416093010/diff/1/talk/session/media/srtpfilter...
talk/session/media/srtpfilter.cc:782: SrtpSession* session =
static_cast<SrtpSession*>(ev->session->user_data);
Do we know what thread this gets invoked from? Would be good to document it to
ensure proper locking.

[joachim, 2015-11-10 16:59:57]

Thanks, also added ThreadChecker to ensure methods are being called from correct
thread.

https://codereview.webrtc.org/1416093010/diff/1/talk/session/media/srtpfilter.cc
File talk/session/media/srtpfilter.cc (right):

https://codereview.webrtc.org/1416093010/diff/1/talk/session/media/srtpfilter...
talk/session/media/srtpfilter.cc:782: SrtpSession* session =
static_cast<SrtpSession*>(ev->session->user_data);
On 2015/11/10 01:25:59, juberti wrote:
> Do we know what thread this gets invoked from? Would be good to document it to
> ensure proper locking.

Done.

[juberti, 2015-11-10 17:20:36]

https://codereview.webrtc.org/1416093010/diff/40001/talk/session/media/srtpfi...
File talk/session/media/srtpfilter.cc (right):

https://codereview.webrtc.org/1416093010/diff/40001/talk/session/media/srtpfi...
talk/session/media/srtpfilter.cc:493: thread_checker_.DetachFromThread();
Remind me - is this called on a different thread than the worker thread? If so,
add a comment to explain this.

[joachim, 2015-11-10 17:30:26]

https://codereview.webrtc.org/1416093010/diff/40001/talk/session/media/srtpfi...
File talk/session/media/srtpfilter.cc (right):

https://codereview.webrtc.org/1416093010/diff/40001/talk/session/media/srtpfi...
talk/session/media/srtpfilter.cc:493: thread_checker_.DetachFromThread();
On 2015/11/10 17:20:35, juberti wrote:
> Remind me - is this called on a different thread than the worker thread? If
so,
> add a comment to explain this.

You're right, looks like this is always called from the worker thread. No need
to detach the ThreadChecker then.

[juberti, 2015-11-10 17:51:08]

lgtm

[joachim, 2015-11-10 19:55:45]

The CQ bit was checked by jbauch@webrtc.org

[commit-bot: I haz the power, 2015-11-10 19:55:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1416093010/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1416093010/60001

[commit-bot: I haz the power, 2015-11-10 20:00:59]

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

[commit-bot: I haz the power, 2015-11-10 20:00:59]

Try jobs failed on following builders:
  presubmit on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/presubmit/builds/1667)

[joachim, 2015-11-10 20:07:34]

On 2015/11/10 20:00:59, commit-bot: I haz the power wrote:
> Try jobs failed on following builders:
>   presubmit on tryserver.webrtc (JOB_FAILED,
> http://build.chromium.org/p/tryserver.webrtc/builders/presubmit/builds/1667)

Justin, could you please confirm from your webrtc.org address, or should I land
this manually once the trybots are green?

[juberti1, 2015-11-10 21:04:51]

juberti@webrtc.org changed reviewers:
+ juberti@webrtc.org

[juberti1, 2015-11-10 21:04:52]

lgtm

[joachim, 2015-11-10 21:21:51]

The CQ bit was checked by jbauch@webrtc.org

[commit-bot: I haz the power, 2015-11-10 21:22:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1416093010/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1416093010/60001

[commit-bot: I haz the power, 2015-11-10 21:56:04]

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

[commit-bot: I haz the power, 2015-11-10 21:56:05]

Try jobs failed on following builders:
  android_arm64_rel on tryserver.webrtc (JOB_TIMED_OUT, no build URL)

[joachim, 2015-11-10 22:08:09]

The CQ bit was checked by jbauch@webrtc.org

[commit-bot: I haz the power, 2015-11-10 22:08:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1416093010/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1416093010/60001

[commit-bot: I haz the power, 2015-11-10 22:48:44]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-11-10 22:48:52]

Patchset 4 (id:??) landed as
https://crrev.com/9cafd972779ed7b25886ab276e0ede7b7a8b76a1
Cr-Commit-Position: refs/heads/master@{#10591}

[phoglund, 2015-11-13 14:54:54]

A revert of this CL (patchset #4 id:60001) has been created in
https://codereview.webrtc.org/1442863003/ by phoglund@webrtc.org.

The reason for reverting is: Unfortunately this breaks an internal downstream
project since we have an ancient libsrtp. Reverting until we can figure out how
to update our libsrtp..