UserAgent: Mozilla/5.0 (X11; CrOS x86_64 9901.16.2017) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.23 Safari/537.36

Steps to reproduce the problem:
When compiling Chromium from source for ChromeOS following the Simple Chrome guide (https://chromium.googlesource.com/chromiumos/docs/+/master/simple_chrome_workflow.md), syncing the source repos fail with a reference is not a tree error

What is the expected behavior?

What went wrong?
The DEPS file for chromium/src release 68.0.3440.61 points to nonexistent webrtc/src commit 350e48ae5ad0e63f9d600dd87cc47799abab5278

Did this work before? N/A 

Chrome version: 68.0.3440.61  Channel: n/a
OS Version: 
Flash Version: