More cleanups in FrameStats
1. Separated HostFrameStats and ClientFrameStats. This will allow to
track host and client stats separately.
2. Added FrameStatsConsumer interface to allow verify that FrameStats
are generated correctly.
3. Added VideoRenderer::GetFrameStatsConsumer() and changed
WebrtcVideoRendererAdapter to get VideoRenderer instead of
FrameConsumer, so now the adapter can report FrameStats.
BUG=621691
Review-Url: https://codereview.chromium.org/2113523007
Cr-Commit-Position: refs/heads/master@{#403953}
24 files changed