Google have released a new headless version of their Chrome browser which can be used for testing with Selenium Webdriver.
Read this post on Friendly tester for more details: New Headless Chrome With Selenium WebDriver. Also Google Developers site has a Getting Started page for those who wish to use the new headless chrome browser in their selenium webdriver tests.
There are a number of different ChromeDriver options (and for the other browsers too) that allow us to control how the browser starts up. In this example we see how Chrome is started when no options are selected:
Using the following options we can specify that Chrome start without the warning message and that it starts maximised.
var chromeOptions = new ChromeOptions();
driver = new ChromeDriver(chromeOptions);