040b79ff7e
To be used when a metric is used in different modes such as real-time vs screenshare (will be done in https://codereview.webrtc.org/1564923008/). BUG=webrtc:5283 Review URL: https://codereview.webrtc.org/1567013004 Cr-Commit-Position: refs/heads/master@{#11461}