Data from the UMA Sampling Profiler shows that blink::scheduler::internal::TaskQueueImpl::UpdateDelayedWakeUp() is executing for an additional 10ms at startup on the renderer process compositor thread on 64-bit Chrome on Windows. During steady-state execution the increase is 1.9% of non-idle execution time. This occurred in the 67.0.3373.0 Canary release.

The responsible CL appears to be https://chromium.googlesource.com/chromium/src.git/+/9ad7a1161ea9c4f9735866127b7352cd23586a75

Execution profile difference of Canary 67.0.3372.0 vs. 67.0.3373.0: https://uma.googleplex.com/p/chrome/callstacks?sid=c7db1710feee80787617329f19fc8eb9