Support WebRTC "release" builds

[paynerc]

I'm not sure if you have seen this or not yet... I had been asking our contacts within Google to get information about how we target their "release" builds and they finally wrote this... and then forgot to tell me it was there until I asked again the other day:

https://groups.google.com/forum/#!topic/discuss-webrtc/UgfnLoI_Dhg

Is this something that we can add support for in these scripts? I think it would be useful to be able to not only target the bleeding edge, but a "stable" (ha ha ha) release branch (per the suggestion of Justin Uberti in a previous discussion we had).

[McPo]

https://chromium.googlesource.com/external/webrtc/+/branch-heads/47

Shows the commit made for the latest WebRTC release, where 47 is the latest Chrome build (WebRTC releases are synchronized with Chrome)

Within the message you will notice the following field

(cherry picked from commit dfa2815b4f606a58ede5c0214e08a1d5d26d3639)

You want to use the cherry picked commit hash, when pulling down webrtc. i.e.

get_webrtc dfa2815b4f606a58ede5c0214e08a1d5d26d3639

Will get WebRTC 47.

There are several other commit hashes in the commit message but they will all fail in various ways. You should only use the cherry-picked hash.

[McPo]

Forget what I detailed above, that will build all commits up to and including the cherry picked commit. ie changes which arn't in the stable release will make there way into the version you are building.

Instead an initial

gclient sync --with_branch_heads

Is required to pull the release branch then

get_webrtc 04be7b85565a658539c4f4161c54c42673aedc85

Will work as it should.

[deano2390]

Where are you getting 04be7b85565a658539c4f4161c54c42673aedc85 from in your revised instructions?

[McPo]

https://chromium.googlesource.com/external/webrtc/+/branch-heads/47 The parent field in the header, do a Ctrl+F for it.