UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36

Steps to reproduce the problem:
1. When i run gn gen out/Name-folder in the chromium/src directory it says that gn wasn't found. I've installed depot_tools and added it to the PATH variabile like this 
C:\src\depot_tools;C:\other\..\..\python\..
And when i type where python on a new cmd shell it doesn't display anything, but if i run it inside the depot_tools directory the output will be the following:
C:\src\depot_tools\python.bat
2. 
3. 

What is the expected behavior?
To build chromium

What went wrong?
Described above

Did this work before? N/A 

Chrome version: 67.0.3396.87  Channel: stable
OS Version: 10.0
Flash Version: 

I'm a windows 10 user.