Add MediaSessionWebRTC to fieldtrial_testing_config

This CL adds MediaSessionWebRTC to fieldtrial_testing_config. Since that
enables the feature on browser tests, this also explicitly disables it
for the pixel tests since adding text to the PiP window complicates the
pixel test.

Change-Id: Ie2a9fe345af7f929d18e4d5701c88c23acae45b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2822815
Reviewed-by: Fran├žois Beaufort <beaufort.francois@gmail.com>
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#874854}
GitOrigin-RevId: 8609f2a10e2509ed51231cbe386f1a429796dcba
1 file changed