Google Chrome 38 introduced the new \"Device Mode & Mobile Emulation\" functionality in devtools. In addition to choosing a device for emulation, it is also possible to
Indeed C# Selenium latest (3.11) has NetworkConditions added. Now you can use it like this:
var driver = new ChromeDriver(pathToDriver);
driver.NetworkConditions = new ChromeNetworkConditions()
{ DownloadThroughput = 5000, UploadThroughput = 5000, Latency = TimeSpan.FromMilliseconds(5) };
The problem is it's not yet usable because of the bug
https://github.com/SeleniumHQ/selenium/issues/5693
So .Net guys will have to wait until 3.12 Selenium Release.