Generate rtc_base/ssl_roots.h

This directory contains a script to generate the content of rtc_base/ssl_roots.h, to update the SSL roots shipped by WebRTC follow this instructions:

1. Download roots.pem from pki.goog.

2. Launch the script:

$ python tools_webrtc/sslroots/generate_sslroots.py roots.pem

3. Step 2 should have generated an ssl_roots.h file right next to roots.pem.

4. Open rtc_base/ssl_roots.h, manually remove the old certificates and paste the ones from the ssl_roots.h file.

5. Delete the generated ssl_roots.h and roots.pem before creating the CL.