Disable chrome download multiple files confirmation

Question

I developed a crawler with ruby watir-webdriver that downloads some files from a page. My problem is that when I click to download the second file, Chrome opens a bar in the

Answer 1

As of Chrome 56.0.2924.87, February 17, 2017, the only preference you need to set (however you set them for your webdriver) is:

'profile.default_content_setting_values.automatic_downloads': 1

Giving an updated answer because most answers here use outdated preferences or show other preferences that are unnecessary.