Measure observed merge delay and export to metric (#921)
Measure observed merge delay and export to metric (#921)


AlCutter/trillian,codingllama/trillian,daviddrysdale/trillian,google/trillian,AlCutter/trillian,gdbelvin/trillian,Martin2112/trillian,daviddrysdale/trillian,codingllama/trillian,RJPercival/trillian,Martin2112/trillian,gdbelvin/trillian,google/trillian,daviddrysdale/trillian,gdbelvin/trillian,Martin2112/trillian,RJPercival/trillian