Just as we track code, data, and cache sizes for Chrome in UMA: https://uma.googleplex.com/p/chrome/histograms/?endDate=20180528&dayCount=1&histograms=Android.PackageStats.CacheSize%2CAndroid.PackageStats.CodeSize%2CAndroid.PackageStats.DataSize&fixupData=true&showMax=true&filters=platform%2Ceq%2CA%2Cchannel%2Ceq%2C4%2Cisofficial%2Ceq%2CTrue&implicitFilters=isofficial it would be nice to also do so on the waterfall, so we can catch any regressions in this.

Rough proposal would be to add a test that just starts chrome and inspects the size of chrome on disk.