If you have already Chrome installed then:
If you don't then:
Check current available version of libwidevine: https://dl.google.com/widevine-cdm/current.txt .
Download and extract the current version:
In the extracted folder:
Then restart the browser and Netflix should be able to play movies.
sudo ln -fs /opt/google/chrome/libwidevinecdm.so /usr/lib/chromium/libwidevinecdm.so
If you don't then:
Check current available version of libwidevine: https://dl.google.com/widevine-cdm/current.txt .
Download and extract the current version:
wget https://dl.google.com/widevine-cdm/1.4.8.1008-linux-x64.zip
unzip 1.4.8.1008-linux-x64.zip
In the extracted folder:
sudo mv libwidevinecdm.so /usr/lib/chromium
sudo chmod 644 /usr/lib/chromium/libwidevinecdm.so
Then restart the browser and Netflix should be able to play movies.