GitLab

This CL resolves comments in 2055143002 after CL being committed:

* Move Initialize() function to protocol::VideoRenderer interface
* Rename JniFrameConsumer to JniVideoRenderer
* Resolves other comments

BUG=385924

Review-Url: https://codereview.chromium.org/2101833002
Cr-Commit-Position: refs/heads/master@{#403263}