GitLab

This CL changes the ownership of PeerConnectionTracker, as a preparation
to Onion souping it.

Reason: when in Blink, there is not a class corresponding to RenderThreadImpl.

BUG=787254
R=guidou@chromium.org, haraken@chromium.org

Change-Id: Ieff1e622d0226547632a1616c3e6c088961d91fa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1845802Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Antonio Gomes <tonikitoo@igalia.com>
Cr-Commit-Position: refs/heads/master@{#707339}