- Make shared EGL context used for HW video decoding member
of decoder factory class.
- Add new Peer connection factory method to initialize shared
EGL context.

This provides an option to use single peer connection factory
in the application and create peer connections from the same
factory and reinitialize shared EGL context for video
decoding HW acceleration.

R=wzh@webrtc.org

Review URL: https://codereview.webrtc.org/1304063011 .

Cr-Commit-Position: refs/heads/master@{#9838}
10 files changed