there's no easy way to inject the Clock in ScreenshareLayers under normal use. To allow faking the clock, rtc::TimeMillis is used instead. Bug: webrtc:10365 Change-Id: I46c7f76514672190a0f0f5816a2c858bc6c76fa4 Reviewed-on: https://webrtc-review.googlesource.com/c/125189 Reviewed-by: Rasmus Brandt <brandtr@webrtc.org> Commit-Queue: Sebastian Jansson <srte@webrtc.org> Cr-Commit-Position: refs/heads/master@{#26946}