I think we can add "ssl_keylog_file_path" to CronetEngine experimental options.

I don't think anyone else has any cycle. I will give it a try.

Thanks. I can try this weekend if you don't get to it first. 

Do we want experimental option or a real API? Don't care much for the short term, but want to make sure we don't end up with a bunch of hidden APIs and this seems like something we would probably want for the long term. 

Talked to davidben@, QUIC has its own crypto stack, so SSLKeyLogFile won't be applicable there. This will only be useful for HTTP/2 traffic.

I will have a CL out for review shortly. Will keep this as an experimental API for now. 

Hmm... we need the QUIC logging more than anything else. How does QUIC key dumping currently work?

I followed up on the email thread.

On when to expose this as a stable API, we will need to wait until crbug.com/458365 is resolved. Setting SSLKEYLOGFILE isn't safe to do with multiple CronetEngines right now.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/da7f770292b2122e8d20386bbe286d9578a302b1

commit da7f770292b2122e8d20386bbe286d9578a302b1
Author: xunjieli <xunjieli@chromium.org>
Date: Mon Mar 28 16:36:36 2016

Plumb SSLKEYLOGFILE from Cronet to net

This will be useful to debug HTTP/2 traffic.

BUG= 598002 

Review URL: https://codereview.chromium.org/1833203002

Cr-Commit-Position: refs/heads/master@{#383504}

[modify] https://crrev.com/da7f770292b2122e8d20386bbe286d9578a302b1/components/cronet/android/cronet_url_request_context_adapter.cc
[add] https://crrev.com/da7f770292b2122e8d20386bbe286d9578a302b1/components/cronet/android/test/javatests/src/org/chromium/net/ExperimentalOptionsTest.java
[modify] https://crrev.com/da7f770292b2122e8d20386bbe286d9578a302b1/components/cronet/android/url_request_context_adapter.cc
[modify] https://crrev.com/da7f770292b2122e8d20386bbe286d9578a302b1/components/cronet/url_request_context_config.cc
[modify] https://crrev.com/da7f770292b2122e8d20386bbe286d9578a302b1/components/cronet/url_request_context_config.h
[modify] https://crrev.com/da7f770292b2122e8d20386bbe286d9578a302b1/components/cronet/url_request_context_config_unittest.cc

Android side is done. Misha is working on iOS so I will leave this bug open. Again since this doesn't cover QUIC, so I will lower the priority to P2. Please re-adjust if needed.

mef@ will verify that its available on iOS.

The iOS support was added as part of initial implementation of Cronet for iOS with C API for GRPC support: https://chromium.googlesource.com/chromium/src/+/06eab3e8e64eacef30f15299ee7c3ad32df2840b