Add macros for ability to log samples that are added to histograms (RTC_LOGGED_*).

Adds logging of:
- video stats that are recorded when a stream is removed
- bitrate stats that are recorded at the end of a call
- initial bwe rampup stats

BUG=

Review URL: https://codereview.webrtc.org/1788783002

Cr-Original-Commit-Position: refs/heads/master@{#12133}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 58d992e02511219ec59b13589a30e4d74d420da3
10 files changed